vboot2: Add crypto functions

This is the first of several CLs adding a more memory- and
code-efficient firmware verification library.  This CL adds the crypto
library (modified from firmware/lib/cryptolib) and unit tests for it.

BUG=chromium:370082
BRANCH=none
TEST=make clean && VBOOT2=1 COV=1 make

Change-Id: I4240eab227bb197cacc6c8e7a6397127d74414a2
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/199578
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
12 files changed