Add link firmware branch configs.

BUG=chrome-os-partner:12148
TEST=cbuildbot_config_unittest

Change-Id: Iff31aa5bb485bbdea365550d686dd4b06135a11c
Reviewed-on: https://gerrit.chromium.org/gerrit/29037
Reviewed-by: David McMahon <djmm@chromium.org>
Reviewed-by: Eric Blake <eblake@chromium.org>
Tested-by: Eric Blake <eblake@chromium.org>
1 file changed