futility: updater: Scan patch files for the signer_config manifest

To migrate the archive manifest generation from `setvars.sh` to
`signer_config.csv`, we have to find the patch files (rootkey.*,
vblock_?.*, gscvd.*) in the signer_config manifest builder.

Also updated the comments for how the signer_config works.

BUG=b:251040363
TEST=make; run test
BRANCH=None

Change-Id: I6e30b7fc55fda2b24f7809a8f2215bb9af1117af
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3937843
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
1 file changed