image_signing: Remove legacy unified build feature

This feature was originally implemented before go/cros-unibuild-signing.
It only provided basis support to continue testing unibuilds, but didn't
deal with the actual required model specific cases.

Unibuilds have already been migrated away from this, so this feature is
now obsolete.

BUG=None
TEST=~/trunk/src/platform/vboot_reference/scripts/image_signing/sign_official_build.sh
recovery ../build/images/coral/latest/recovery_image.bin
../platform/vboot_reference/tests/devkeys
BRANCH=None

Change-Id: I58b569b97f0bf42a927a851e7bc0559cb1e26200
Reviewed-on: https://chromium-review.googlesource.com/660805
Commit-Ready: C Shapiro <shapiroc@google.com>
Tested-by: C Shapiro <shapiroc@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed