mb/google/poppy/variants/baseboard: Add gpio-keys ACPI node for PENH

This change uses gpio_keys driver to add ACPI node for pen eject event.

TEST=Verified using evtest that pen eject event results in events as

Change-Id: I6019d633f4337137bb9fbba770040cb5b30da773
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://review.coreboot.org/25147
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed