cros_update_firmware: move to contrib

This code isn't supported by the build team, so move it to contrib/.

BUG=None
TEST=None

Change-Id: I20340e243520caef0c2a08d8ba6c7d4cec849f1c
Reviewed-on: https://chromium-review.googlesource.com/1178328
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: YH Lin <yueherngl@chromium.org>
1 file changed