futility: updater: write multiple sections in recovery RW update

The write_firmware_sections now supports writing multiple sections in
one invocation so we can pass all RW sections to it for the recovery
update.

On Brya, the total execution time may be reduced from 4 mins to
1.5 mins.

BUG=b:221137867
TEST=build and run test
BRANCH=None

Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Change-Id: Ifbc67327a02096e027c1e2025485ebb17645a71d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3490387
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
1 file changed