mainboard/google/poppy: Provide cros_gpio variant API

Add support for ChromeOS GPIO ACPI table information by providing weak
implementation from the baseboard.

BUG=b:37375693

Change-Id: I641afe6bb45f106ddebde081a8ac2c64278ebeb9
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19324
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
3 files changed