volteer: enable extpower gpio support and add configs

Enable CONFIG_PLATFORM_EC_EXTPOWER_GPIO, and add the configs for the
pin and interrupt needed in gpio_map.h

BUG=b:172720290
TEST=see TEST of CL:2527703

Cq-Depend: chromium:2527703
Change-Id: I026e1942d752668c27746b73e778c56d8cd6a096
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/zephyr-chrome/+/2527663
Tested-by: Jack Rosenthal <jrosenth@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>
2 files changed