new_variant: use coreboot upstream for zork
With zork moving to coreboot upstream, modify the automation scripts
and documentation to use upstream instead of the trembyle-bringup
branch (which was in coreboot-zork).
BUG=b:157570490
TEST=create the "grue" variant of trembyle by following the steps
in testdata/grue.md.
Change-Id: I48ba17d779bd940d987a10f63027d7ef848e6de0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2295692
Tested-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Raul E Rangel <rrangel@chromium.org>
Commit-Queue: Paul Fagerburg <pfagerburg@chromium.org>
3 files changed
