uprev_scp_firmware: Pack scp-dual.img if it exists

Some platforms needs more than one SCP image e.g. Geralt.
Optionally look for and pack scp-dual.img if it exists.

BUG=b:291845154
TEST=./uprev_scp_firmware.sh -b geralt -v 15842.13.0

Change-Id: Ib92ce174aea9203402f9644a6d4368ce8b2e9520
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5508477
Tested-by: Fei Shao <fshao@chromium.org>
Reviewed-by: Pin-yen Lin <treapking@chromium.org>
Commit-Queue: Fei Shao <fshao@chromium.org>
1 file changed