Add MBEDTLS_SSL_CONF_TRANSPORT

Follow the model of `MBEDTLS_SSL_CONF_ENDPOINT`. This saves a small
amount - most of the saving was already acheived via`
MBEDTLS_SSL_TRANSPORT_IS_TLS` but we can scrape out a little more by
totally eliminating `ssl->conf->transport` references.

Signed-off-by: Kevin Bracey <kevin.bracey@arm.com>
diff --git a/programs/ssl/query_config.c b/programs/ssl/query_config.c
index 21800bb..bc6499d 100644
--- a/programs/ssl/query_config.c
+++ b/programs/ssl/query_config.c
@@ -2778,6 +2778,14 @@
     }
 #endif /* MBEDTLS_SSL_CONF_ENDPOINT */
 
+#if defined(MBEDTLS_SSL_CONF_TRANSPORT)
+    if( strcmp( "MBEDTLS_SSL_CONF_TRANSPORT", config ) == 0 )
+    {
+        MACRO_EXPANSION_TO_STR( MBEDTLS_SSL_CONF_TRANSPORT );
+        return( 0 );
+    }
+#endif /* MBEDTLS_SSL_CONF_TRANSPORT */
+
 #if defined(MBEDTLS_SSL_CONF_CERT_REQ_CA_LIST)
     if( strcmp( "MBEDTLS_SSL_CONF_CERT_REQ_CA_LIST", config ) == 0 )
     {