project-lakitu: add verified boot support to grub.cfg on ARM64

Align boot process with x86 systems:

- Use the same menu/choices structure in grub.cfg
- Extract dm verity information from a kernel partition
  and pass it to kernel through cmdline

It's still not 100% match funcitonally: kernel B is not populated
because size does not allow doing it yet.

BUG=b/179918454
TEST=presubmit
RELEASE_NOTE=None

Change-Id: I334ab1a3d4bda43c22a7df7ffe4c9a1a75e02327
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/13230
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
1 file changed