add non-gcc arm_neon support

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/common.h b/library/common.h
index 78d71fd..cc58bf4 100644
--- a/library/common.h
+++ b/library/common.h
@@ -170,8 +170,8 @@
     size_t i = 0;
 #if defined(MBEDTLS_EFFICIENT_UNALIGNED_ACCESS)
 #if defined(__ARM_NEON) && \
-    (defined(__GNUC__) && !defined(__clang__) && \
-    __GNUC__ >= 7 && __GNUC_MINOR__ >= 3)
+    (!defined(MBEDTLS_COMPILER_IS_GCC) || \
+    (defined(MBEDTLS_COMPILER_IS_GCC) && __GNUC__ >= 7 && __GNUC_MINOR__ >= 3))
     for (; (i + 16) <= n; i += 16) {
         uint8x16_t v1 = vld1q_u8(a + i);
         uint8x16_t v2 = vld1q_u8(b + i);