Split off modules required for VbInit() and VbSelectFirmware()

This makes it more obvious which modules and VbEx*() functions must be
implemented to call these entry points.

This change only moves functions between modules and adds two
link-test binaries; it doesn't change any functionality.

BUG=chromium-os:39262
BRANCH=none
TEST=make && make runtests

Change-Id: If3edf0b1989b631f0e7ad18de7ccdad8315181b5
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/44076
Reviewed-by: Bill Richardson <wfrichar@chromium.org>
9 files changed