project-lakitu: use correct serial console device on ARM64

Use ttyAMA1 device on ARM as a serial console where there are no
ttySx devices.

BUG=b/179817368
TEST=presubmit
RELEASE_NOTE=None

Change-Id: I1f0062e8d0d2a213a9d70b40c11084c0584268b2
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/14556
Reviewed-by: Roy Yang <royyang@google.com>
Reviewed-by: Ke Wu <mikewu@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
2 files changed