rwsig: add host command for getting rwsig status

Add a new host command EC_CMD_RWSIG_CHECK_STATUS for getting rwsig
status and rw firmware hash.  This command is used to check the RW
signature of newly updated RW image.

A new subcommand is also added to ectool.

BRANCH=none
BUG=b:37584134
TEST=on rose board `ectool rwsigstatus` works

Change-Id: I33d8709f5248d3a4b8bedb36ded84a93dc8c971f
Signed-off-by: Wei-Ning Huang <wnhuang@google.com>
Reviewed-on: https://chromium-review.googlesource.com/485079
Commit-Ready: Wei-Ning Huang <wnhuang@chromium.org>
Tested-by: Wei-Ning Huang <wnhuang@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
3 files changed