posix_ec: enable CONFIG_PLATFORM_EC

To bulid platform/ec module.

BUG=b:167590251
TEST=compile and run with platform/ec in ZEPHYR_MODULES

Cq-Depend: chromium:2427089
Change-Id: If44add4c61ef7557b3b57ded1ee6b6f3730a6824
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/zephyr-chrome/+/2432317
Tested-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
1 file changed