krabby: configure led
krabby: configure led

Add basic LED implementation for Krabby.

BUG=none
TEST=ectool led (power|battery) <color>
     manually verify
BRANCH=none

Signed-off-by: Ting Shen <c671d3efec3d7e7e285f3788bf0d1ba4c8605b78@google.com>
Change-Id: I6117e44b404c21ab81126b8e0c317f07f4814e79
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3389068
Tested-by: Ting Shen <c671d3efec3d7e7e285f3788bf0d1ba4c8605b78@chromium.org>
Auto-Submit: Ting Shen <c671d3efec3d7e7e285f3788bf0d1ba4c8605b78@chromium.org>
Reviewed-by: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>
Commit-Queue: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec