CHERRY-PICK: Stout: Add battery firmware update command.

Add command for updating battery firmware.

TEST="mosys battery update" on stout platform.
BUG=chrome-os-partner:17046
BRANCH=stout

Change-Id: I1f75af1050b0995a06353194e318ea7cfb49761f
Original-Change-Id: I9c84ef2c3e89c6091ef5cae9f822e5ea2b40463f
Reviewed-on: https://gerrit.chromium.org/gerrit/40422
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: Shawn Nematbakhsh <shawnn@chromium.org>
Tested-by: Shawn Nematbakhsh <shawnn@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/41500
Reviewed-by: Shawn Nematbakhsh <shawnn@chromium.org>
5 files changed