fbdev: omapfb: encoder-opa362: fix included headers

The driver has been switched to gpiod API, so it should include
gpio/consumer.h instead of gpio.h and of_gpio.h.

With of_gpio.h no longer included we need mod_devicetable.h for
of_device_id definition.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>