Rename function to conform to the library

Signed-off-by: gabor-mezei-arm <gabor.mezei@arm.com>
diff --git a/tests/include/test/psa_crypto_helpers.h b/tests/include/test/psa_crypto_helpers.h
index 522fbae..8a8c37e 100644
--- a/tests/include/test/psa_crypto_helpers.h
+++ b/tests/include/test/psa_crypto_helpers.h
@@ -192,7 +192,7 @@
  * permissions of other usage policies
  * (like PSA_KEY_USAGE_SIGN_HASH involves PSA_KEY_USAGE_SIGN_MESSGAE).
  */
-psa_key_usage_t update_key_usage_flags( psa_key_usage_t usage_flags );
+psa_key_usage_t mbedtls_test_update_key_usage_flags( psa_key_usage_t usage_flags );
 
 /** Skip a test case if the given key is a 192 bits AES key and the AES
  *  implementation is at least partially provided by an accelerator or