Fix module-import-in-extern-c compiler error

This fixes a compiler error when building C++ projects that use the
'modules' C++ language feature consume Mbed TLS. The specific error is
module-import-in-extern-c, which occurs when `#include`s occur within
`extern C` blocks.

```
$ clang-17 -std=c++20 -fmodules -Itf-psa-crypto/include -Itf-psa-crypto/drivers/builtin/include -o sample sample.cpp
In file included from sample.cpp:8:
In file included from tf-psa-crypto/drivers/builtin/include/mbedtls/private/chachapoly.h:44:
tf-psa-crypto/drivers/builtin/include/mbedtls/private/chacha20.h:26:1: error: import of C++ module '_Builtin_stdint' appears within extern "C" language linkage specification [-Wmodule-import-in-extern-c]
   26 | #include <stdint.h>
      | ^
tf-psa-crypto/drivers/builtin/include/mbedtls/private/chachapoly.h:35:1: note: extern "C" language linkage specification begins here
   35 | extern "C" {
      | ^
1 error generated.
```

This seems to primarily be an issue with clang. See
https://clang.llvm.org/docs/ClangCommandLineReference.html#cmdoption-clang-fmodules

Signed-off-by: zacharykeyessonos <[email protected]>

Author: zacharykeyessonos

include/mbedtls/aes.h

@@ -49,10 +49,6 @@
 /** Invalid input data. */
 #define MBEDTLS_ERR_AES_BAD_INPUT_DATA                    -0x0021
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #if !defined(MBEDTLS_AES_ALT)
 // Regular implementation
 //
@@ -96,6 +92,10 @@ typedef struct mbedtls_aes_xts_context {
 #include "aes_alt.h"
 #endif /* MBEDTLS_AES_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief          This function initializes the specified AES context.
  *

include/mbedtls/aria.h

@@ -38,10 +38,6 @@
 /** Invalid data input length. */
 #define MBEDTLS_ERR_ARIA_INVALID_INPUT_LENGTH -0x005E
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #if !defined(MBEDTLS_ARIA_ALT)
 // Regular implementation
 //
@@ -60,6 +56,10 @@ mbedtls_aria_context;
 #include "aria_alt.h"
 #endif /* MBEDTLS_ARIA_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief          This function initializes the specified ARIA context.
  *

include/mbedtls/camellia.h

@@ -27,10 +27,6 @@
 /** Invalid data input length. */
 #define MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH -0x0026
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #if !defined(MBEDTLS_CAMELLIA_ALT)
 // Regular implementation
 //
@@ -48,6 +44,10 @@ mbedtls_camellia_context;
 #include "camellia_alt.h"
 #endif /* MBEDTLS_CAMELLIA_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief          Initialize a CAMELLIA context.
  *

include/mbedtls/ccm.h

@@ -54,10 +54,6 @@
 /** Authenticated decryption failed. */
 #define MBEDTLS_ERR_CCM_AUTH_FAILED     -0x000F
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #if !defined(MBEDTLS_CCM_ALT)
 // Regular implementation
 //
@@ -98,6 +94,10 @@ mbedtls_ccm_context;
 #include "ccm_alt.h"
 #endif /* MBEDTLS_CCM_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief           This function initializes the specified CCM context,
  *                  to make references valid, and prepare the context

include/mbedtls/chacha20.h

@@ -29,10 +29,6 @@
 /** Invalid input parameter(s). */
 #define MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA         -0x0051
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #if !defined(MBEDTLS_CHACHA20_ALT)
 
 typedef struct mbedtls_chacha20_context {
@@ -46,6 +42,10 @@ mbedtls_chacha20_context;
 #include "chacha20_alt.h"
 #endif /* MBEDTLS_CHACHA20_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief           This function initializes the specified ChaCha20 context.
  *

include/mbedtls/chachapoly.h

@@ -31,10 +31,6 @@
 /** Authenticated decryption failed: data was not authentic. */
 #define MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED          -0x0056
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 typedef enum {
     MBEDTLS_CHACHAPOLY_ENCRYPT,     /**< The mode value for performing encryption. */
     MBEDTLS_CHACHAPOLY_DECRYPT      /**< The mode value for performing decryption. */
@@ -59,6 +55,10 @@ mbedtls_chachapoly_context;
 #include "chachapoly_alt.h"
 #endif /* !MBEDTLS_CHACHAPOLY_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief           This function initializes the specified ChaCha20-Poly1305 context.
  *

include/mbedtls/cmac.h

@@ -20,10 +20,6 @@
 
 #include "mbedtls/cipher.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #define MBEDTLS_AES_BLOCK_SIZE          16
 #define MBEDTLS_DES3_BLOCK_SIZE         8
 
@@ -72,6 +68,10 @@ struct mbedtls_cmac_context_t {
 #include "cmac_alt.h"
 #endif /* !MBEDTLS_CMAC_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief               This function starts a new CMAC computation
  *                      by setting the CMAC key, and preparing to authenticate

include/mbedtls/des.h

@@ -30,10 +30,6 @@
 
 #define MBEDTLS_DES_KEY_SIZE    8
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #if !defined(MBEDTLS_DES_ALT)
 // Regular implementation
 //
@@ -66,6 +62,10 @@ mbedtls_des3_context;
 #include "des_alt.h"
 #endif /* MBEDTLS_DES_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief          Initialize DES context
  *

include/mbedtls/dhm.h

@@ -89,10 +89,6 @@ typedef enum {
     MBEDTLS_DHM_PARAM_K,  /*!<  The shared secret = \c G^(XY) mod \c P. */
 } mbedtls_dhm_parameter;
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 #if !defined(MBEDTLS_DHM_ALT)
 
 /**
@@ -116,6 +112,10 @@ mbedtls_dhm_context;
 #include "dhm_alt.h"
 #endif /* MBEDTLS_DHM_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief          This function initializes the DHM context.
  *

include/mbedtls/ecjpake.h

@@ -32,10 +32,6 @@
 #include "mbedtls/ecp.h"
 #include "mbedtls/md.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /**
  * Roles in the EC J-PAKE exchange
  */
@@ -79,6 +75,10 @@ typedef struct mbedtls_ecjpake_context {
 #include "ecjpake_alt.h"
 #endif /* MBEDTLS_ECJPAKE_ALT */
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * \brief           Initialize an ECJPAKE context.
  *