vboot2: Add official API header file

This is what other firmware should include.  Other firmware must NOT
attempt to include headers from deeper inside the vboot2
implementation; that will likely break as vboot2 is refactored.

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

Change-Id: I63638b03bb108296fa5069e7cc32ee9e25183846
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/233050
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
1 file changed