Glimmer: Add wakeup_input_device_names with tpad wake

Add support for configuring Elan touchpad. This preference
file will tell the power manager to set the Elan trackpad device
to wakeup "enabled" before suspending with lid open and wakeup
"disabled" before suspending with lid closed.

BUG=chrome-os-partner:28298
TEST=`emerge-glimmer chromeos-bsp-glimmer` verify file in place

Change-Id: Ia84d4b3121e202967ddffe232e5b370bd57aea6c
Reviewed-on: https://chromium-review.googlesource.com/196893
Reviewed-by: Yufeng Shen <miletus@chromium.org>
Commit-Queue: Bernie Thompson <bhthompson@chromium.org>
Tested-by: Bernie Thompson <bhthompson@chromium.org>
(cherry picked from commit 804065251800ec4a865e3ce02973137ca68018ee)
Reviewed-on: https://chromium-review.googlesource.com/197550
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
3 files changed