lakitu: add x86 and ARM64 configs for the lakitu board

- Add lakitu_defconfig files for x86 and ARM architecture
- Add trusted root cert to the tree

BUG=b/229784006
TEST=presubmit
RELEASE_NOTE=None

Change-Id: If54ac7b9f6be5264543be47919cd7788c5ceea50
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/31923
Reviewed-by: Roy Yang <royyang@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>