media: max9286: Depend on OF_GPIO

The driver expects struct gpio_chip has of_node field and that field is
only there if CONFIG_OF_GPIO is defined. Fix this by changing the OF
dependency to OF_GPIO.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>