Update SDK to 18438.0.0

Removed sys-power/cpupower

BUG=b/303317695
TEST=presubmit and validation tests
RELEASE_NOTE=None

Change-Id: I0fa8a7ebfc10393d0b0cd14911a1a5d176fd84c6
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/chromiumos-overlay/+/71630
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
2 files changed