Update is_builtin_calling_md() for PKCS#1 v2.1

Since https://github.com/Mbed-TLS/mbedtls/pull/6141 it can "fall back"
to PSA when MD is not available (but will use MD if available, to
preserve backwards compatibility).

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/tests/suites/test_suite_psa_crypto_storage_format.function b/tests/suites/test_suite_psa_crypto_storage_format.function
index 31d3cb4..1fd267a 100644
--- a/tests/suites/test_suite_psa_crypto_storage_format.function
+++ b/tests/suites/test_suite_psa_crypto_storage_format.function
@@ -86,11 +86,19 @@
 {
 #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_PSS)
     if( PSA_ALG_IS_RSA_PSS( alg ) )
+#if defined(MBEDTLS_MD_C)
         return( 1 );
+#else
+        return( 0 );
+#endif
 #endif
 #if defined(MBEDTLS_PSA_BUILTIN_ALG_RSA_OAEP)
     if( PSA_ALG_IS_RSA_OAEP( alg ) )
+#if defined(MBEDTLS_MD_C)
         return( 1 );
+#else
+        return( 0 );
+#endif
 #endif
 #if defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
     if( PSA_ALG_IS_DETERMINISTIC_ECDSA( alg ) )