lulu: Add the servo overlay

Reference the Auron overlay.

BUG=chrome-os-partner:35841
TEST=run 'cros_workon --host start hdctools'
   'sudo emerge hdctools'
   'sudo servod --board=lulu'
BRANCH=none

Change-Id: I84adb6276856e07cdc93f1ba1fc4a7aed2744d30
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Reviewed-on: https://chromium-review.googlesource.com/243441
Reviewed-by: Shawn N <shawnn@chromium.org>
1 file changed