chromeos: On ARM platforms VBNV lives in the EC

This patch renames the x86 way of doing things to
explicitly mention CMOS (which is not available on
our ARM platforms) and adds an implementation to
get VBNV through the Chrome EC. We might want to
refine this further in the future to allow VBNV
in the EC even on x86 platforms. Will be fixed when
that appears. Also, not all ARM platforms running
ChromeOS might use the Google EC in the future, in
which case this code will need additional work.

Signed-off-by: Stefan Reinauer <reinauer@google.com>
BRANCH=none
TEST=needs further changes
BUG=none

Change-Id: Ice09d0e277dbb131f9ad763e762e8877007db901
Reviewed-on: https://chromium-review.googlesource.com/167540
Reviewed-by: David Hendrix <dhendrix@chromium.org>
Tested-by: Stefan Reinauer <reinauer@google.com>
Commit-Queue: Stefan Reinauer <reinauer@google.com>
7 files changed