cloud-init: refactor cloud-init and move to cloud-init-config

refactor cloud-init across different boards and make it under
cloud-init-config

BUG=b/175418043
TEST=presubmit
RELEASE_NOTE=None

Change-Id: I2032e804e14342b5c37f7f33804d5763267504cc
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/9800
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
17 files changed