Cr50: Add "wp" console command to control EC_WP_L

BUG=chrome-os-partner:49959
BRANCH=none
TEST=manual

On the Cr50 console, use the "wp" command to get/set the desired
state. On the EC console, use "gpioget wp_l" to watch it change.

Change-Id: I5978e6116ad0a07a7a61a8356dc1daf79e2397d0
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/373618
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
2 files changed