Guard from reordering DMA wait and post-wait for crypto modules

Author: ccli8

targets/TARGET_NUVOTON/TARGET_M480/crypto/crypto-misc.c

@@ -200,7 +200,10 @@ static void crypto_submodule_prestart(volatile uint16_t *submodule_done)
 static bool crypto_submodule_wait(volatile uint16_t *submodule_done)
 {
     while (! *submodule_done);
-    
+
+    /* Ensure while loop above and subsequent code are not reordered */
+    __DSB();
+
     return true;
 }
 

targets/TARGET_NUVOTON/TARGET_NUC472/crypto/crypto-misc.c

@@ -200,7 +200,10 @@ static void crypto_submodule_prestart(volatile uint16_t *submodule_done)
 static bool crypto_submodule_wait(volatile uint16_t *submodule_done)
 {
     while (! *submodule_done);
-    
+
+    /* Ensure while loop above and subsequent code are not reordered */
+    __DSB();
+
     return true;
 }