futility: updater: create a manifest from the signer config

The signer_config.csv contains almost everything we need for mapping
from models to image files so that can be an alternative when
models/*/setvars.sh files are not available. This can be shared by
/firmware in future.

Verified by comparing the manifest.json from existing firmware updaters
on the following boards: volteer (share target), sarien (no ec), octopus
(custom-label), and hatch (share target).

 for BOARD in volteer sarien octopus hatch; do
   /build/$BOARD/usr/sbin/chromeos-firmwareupdate --unpack test/$BOARD
   jq -S . <test/$BOARD/manifest.json >old
   rm -rf test/$BOARD/models
   futility update --manifest -a test/$BOARD | jq -S . >new
   diff new old >diff.$BOARD

 # all diff.$BOARD are empty, e.g., no difference.

TEST=make; run test

Change-Id: I17393c941d2577a2b1c5f00f60b25e98fa3f3a6f
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3612646
Reviewed-by: Julius Werner <jwerner@chromium.org>
Commit-Queue: Yu-Ping Wu <yupingso@chromium.org>
1 file changed