futility: updater: split 'fast update' into 'diff image' and 'no verify'

Some special quirks (for example preserving ME) may want to use diff
image but still do verification, so we want to change 'fast_update'
config into two flags: 'do_verify' and 'use_diff_image'.

BUG=b:213706510
TEST=build
BRANCH=None

Change-Id: Ia0160918ac58110850dd7f622610398ebfb92b47
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3404061
Reviewed-by: YH Lin <yueherngl@chromium.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
5 files changed