replace target arch macros in padlock

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/padlock.h b/library/padlock.h
index ae5c486..d3ed2c3 100644
--- a/library/padlock.h
+++ b/library/padlock.h
@@ -39,15 +39,11 @@
 #endif
 
 /* Some versions of ASan result in errors about not enough registers */
-#if defined(MBEDTLS_HAVE_ASM) && defined(__GNUC__) && defined(__i386__) && \
-    !defined(MBEDTLS_HAVE_ASAN)
+#if defined(__GNUC__) && defined(MBEDTLS_ARCH_IS_X86) && \
+    defined(MBEDTLS_HAVE_ASM) && !defined(MBEDTLS_HAVE_ASAN)
 
 #define MBEDTLS_VIA_PADLOCK_HAVE_CODE
 
-#ifndef MBEDTLS_HAVE_X86
-#define MBEDTLS_HAVE_X86
-#endif
-
 #include <stdint.h>
 
 #define MBEDTLS_PADLOCK_RNG 0x000C