bdb: Replace sha functions with vb2 library

BDB has its own implementation of SHA256. This patch replaces it with
the one implemented in vb2 library.

BUG=chrome-os-partner:51908
BRANCH=tot
TEST=build runtests

Change-Id: Ida19dd49153a038fc2b2ce481cedf828818aaeaa
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/342121
Reviewed-by: Randall Spangler <rspangler@chromium.org>
5 files changed