gbb_utility: add --flags parameter.

The --flags is added to get/set the "flags" field.

BUG=chrome-os-partner:2317
TEST=gbb_utiltiy --get --flags bios.bin # see flags as 0
     gbb_utility --set --flags=0x3052 bios.bin
     # for version error message for GBB1.0 files,
     # and see flag value changed for GBB1.1+ files
     gbb_utility --get --flags bios.bin
     # flag as 0 for GBB1.0, 0x3052 for GBB1.1+

Change-Id: I7aab62c8fc32ea08b4822e496f543511ff5e5ebc
Reviewed-on: http://gerrit.chromium.org/gerrit/6721
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
3 files changed