Change VbExEc functions to take a devidx parameter

This will be used in subsequent CLs to support PD software sync.  For
now, only devidx=0 is used.

This changes the external vboot API, so must be checked in at the same
time as changes to the u-boot and depthcharge implementations.  For
now, those implementations should simply check if devidx=0 and fail if
it's not.

BUG=chrome-os-partner:30079
BRANCH=none
TEST=make runtests
CQ-DEPEND=CL:208195,CL:208196

Change-Id: Iad3be9d676ac224c4582669bcd67176b39f75c73
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/208210
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
7 files changed