Refactor GPIO EINT code which can be reused among similar SoCs.
BUG=b:80501386
BRANCH=none
TEST=emerge-elm coreboot; emerge-kukui coreboot
Change-Id: Ib01b43cf1aa4082d7d968fe1ef82f75e8cf05b8b
Signed-off-by: Chuanjia Liu <Chuanjia.Liu@mediatek.com>
Reviewed-on: https://review.coreboot.org/c/29837
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>