fbdev: omap/lcd: Remove no-op driver callbacks

Every single one of the OMAP fbdev LCD drivers implements no-op remove,
suspend and resume callbacks for their platform_driver. This is not
necessary as the driver core handles the case where the callbacks are not
set just fine. So they are just unnecessary boilerplate that can be
removed.

Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>