mosys: Updating Ryu to read/write values from ROM

Updated Ryu to use flashrom for updating crossystem fields.

BUG=none
BRANCH=none
TEST=mosys nvram vboot read/write on Ryu.  Additionally, used
crossystem to read/update fields.

Change-Id: Ib0f1560549deacd451c49321e01b43eab1b3dd40
Signed-off-by: Shelley Chen <shchen@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/289666
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Commit-Queue: Puneet Kumar <puneetster@chromium.org>
3 files changed