Add gpio.h header for dt-bindings. Bug 4078385 Change-Id: Id478947d89f3fb327ee84dbf2dfd6403b0cde6bf Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/c/device/hardware/nvidia/t23x-public-dts/+/2892546 Reviewed-on: https://git-master.nvidia.com/r/c/device/hardware/nvidia/tegra-public-dts/+/3168927 GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>