futility: updater: allow writing multiple sections in one flash command

Add new function 'write_firmware_sections' so we can write update
sections in one write_system_firmware (e.g., flashrom) command.

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

Change-Id: Ia33ec5ac82e1c661457180ec45df6c02beae4ec3
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3490389
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
1 file changed