project-lakitu: Add $LD in loadpin-trigger Makefile

This makes loadpin-trigger to use the correct linker when
building on ARM.

BUG=b/177737248
TEST=tryjob
RELEASE_NOTE=None

Change-Id: Id98f70d326e17e3e1470dd0bd7cbf0ff00ccbd0a
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/11130
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
2 files changed