Move mbed TLS configuration symbol to macro section

The configuration option for the mbed TLS specific hardware acceleration
has to be in the macro section and not in the device capabilities
section in targets.json.

The option has also been renamed to better reflect its function.

Author: yanesca

features/mbedtls/platform/inc/platform_mbed.h

@@ -21,6 +21,6 @@
 #define MBEDTLS_ENTROPY_HARDWARE_ALT
 #endif
 
-#if defined(DEVICE_CRYPTO)
+#if defined(MBEDTLS_HW_SUPPORT)
 #include "mbedtls_device.h"
 #endif