of_gpio.h is deprecated in upstream Linux and may be removed soon. Get
ahead of things and remove it. Most of these drivers already use the
gpiod API.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/20076
Signed-off-by: Robert Marko <robimarko@gmail.com>