buildgcc: don't download python and expat if disabled

Change-Id: I18cb1426e935c46ead30c72685829c20d186f9d8
Signed-off-by: Jonathan A. Kollasch <jakllsch@kollasch.net>
Reviewed-on: http://review.coreboot.org/423
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

util/crossgcc/buildgcc

@@ -211,7 +211,9 @@ if [ $SKIPGDB -eq 1 ]; then
 	fi
 fi
 if [ $SKIPPYTHON -eq 1 ]; then
+	PYTHON_ARCHIVE=""
 	PYTHON_PACKAGE=""
+	EXPAT_ARCHIVE=""
 	EXPAT_PACKAGE=""
 fi