Add VbExEcGetExpectedRWHash()

This is used by vboot to retrieve the precomputed hash of the expected
EC image, which requires reading less data from EEPROM than getting
the entire EC image.

BUG=chrome-os-partner:17606
BRANCH=spring
TEST=none; just a new API not used yet

Change-Id: I226643144280acabba147d345ef1f83a77a91fbc
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/42566
1 file changed