move EOL boards to overlays

This helps us slowly deprecate this repo.

BUG=chromium:937711
TEST=precq passes
CQ-DEPEND=CL:1535559

Change-Id: Id65a586b74e270286cffc8b009c784cfb3fe525d
Reviewed-on: https://chromium-review.googlesource.com/1535563
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Tai-Hsu Lin <sheckylin@chromium.org>
9 files changed