Add a get_board() method to servod.

The new method is meant to support clients that need to determine
their behavior based on the kind of DUT board the Servo is
controlling.  The method returns the board (if any) that was passed
via the --board option.

BUG=chromium-os:35804
TEST=integration testing with a corresponding autotest client

Change-Id: Ic7f0d6467c5ab7faf030e0ec26a938509bd6ae03
Reviewed-on: https://gerrit.chromium.org/gerrit/45621
Reviewed-by: Simran Basi <sbasi@chromium.org>
Tested-by: Richard Barnette <jrbarnette@chromium.org>
Reviewed-by: Todd Broch <tbroch@chromium.org>
Reviewed-by: Tom Wai-Hong Tam <waihong@chromium.org>
Commit-Queue: Richard Barnette <jrbarnette@chromium.org>
2 files changed