require clang 4 for testing

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 1d9f32d..b7f4f4d 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -4354,6 +4354,12 @@
     armc6_build_test "-O1 --target=aarch64-arm-none-eabi -march=armv8-a+crypto"
 }
 
+support_build_sha_armce() {
+    # clang >= 4 is required to build with SHA extensions
+    ver="$(clang --version|grep version|sed -E 's#.*version ([0-9]+).*#\1#')"
+    [ "${ver}" -ge 4 ]
+}
+
 component_build_sha_armce () {
     # Test variations of SHA256 Armv8 crypto extensions
     scripts/config.py unset MBEDTLS_SHA256_USE_A64_CRYPTO_IF_PRESENT