Add more vboot_api_kernel tests BUG=chromium-os:38139 BRANCH=none TEST=make runtests && FEATURES=test emerge-daisy vboot_reference Change-Id: Ib280b80ba707f8a2141d728f78ae296774b1301a Signed-off-by: Randall Spangler <rspangler@chromium.org> Reviewed-on: https://gerrit.chromium.org/gerrit/42669