(factory-1412.B) Sync vbutil_what_keys with ToT.

Merged CLs:

 - Enhance vbutil_what_keys to work on BIOS images too.
   https://gerrit.chromium.org/gerrit/13014

 - Add Stumpy MP key info to vbutil_what_keys
   https://gerrit.chromium.org/gerrit/15271

 - vbutil_what_keys - any file 8M or less is a BIOS image
   https://gerrit.chromium.org/gerrit/15359

BUG=chrome-os-partner:7878
TEST=Tested inside each CL.

Change-Id: Ia89dda0bf8d51efb957f28b558dcd05f6a34b038
Reviewed-on: https://gerrit.chromium.org/gerrit/16229
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
1 file changed