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
- Use lakitu_defconfig files for Kokoro builds

With these changes standalone kernel build can produce
kernel usable by the COS VM.

BUG=b/204367125
TEST=presubmit
RELEASE_NOTE=None

Change-Id: I2e587160d778ff246b88306024579417ab3b2e5a
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/28960
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Meena Shanmugam <meenashanmugam@google.com>
4 files changed