vboot2: Add verification for common vb2 struct header

All new-style structs have a common header.  This adds a verification
function for that common header, and tests for it.

BUG=chromium:423882
BRANCH=none
TEST=VBOOT2=1 make runtests

Change-Id: I668486e77f7200c10b43aa2d17b4dd6639e5538e
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/225459
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
5 files changed