Fix the comments of some guards

Signed-off-by: Pengyu Lv <pengyu.lv@arm.com>
diff --git a/include/mbedtls/aesni.h b/include/mbedtls/aesni.h
index 49bc9e1..0da40a0 100644
--- a/include/mbedtls/aesni.h
+++ b/include/mbedtls/aesni.h
@@ -176,6 +176,6 @@
 #endif
 
 #endif /* MBEDTLS_AESNI_HAVE_CODE */
-#endif  /* MBEDTLS_AESNI_C */
+#endif /* MBEDTLS_AESNI_C && (MBEDTLS_HAVE_X86_64 || MBEDTLS_HAVE_X86) */
 
 #endif /* MBEDTLS_AESNI_H */