Use gpio_keys driver to add ACPI node for pen eject event. Also
setting gpio wake pin for wake events.
BUG=b:176213181
TEST=emerge-volteer coreboot chromeos-bootimage
Signed-off-by: Pan Sheng-Liang <sheng-liang.pan@quanta.corp-partner.google.com>
Change-Id: If0959df5d0f069048777df81b0d4092ea90314eb
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49967
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>