OMAP: DSS2: move timing functions

Move check/set/get_timings() from omap_dss_device to omap_dss_driver.

This is part of a larger patch-set, which moves the control from omapdss
driver to the display driver.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
diff --git a/drivers/video/omap2/omapfb/omapfb-main.c b/drivers/video/omap2/omapfb/omapfb-main.c
index b327ee0..8aed12a 100644
--- a/drivers/video/omap2/omapfb/omapfb-main.c
+++ b/drivers/video/omap2/omapfb/omapfb-main.c
@@ -705,9 +705,9 @@
 	var->width              = -1;
 	var->grayscale          = 0;
 
-	if (display && display->get_timings) {
+	if (display && display->driver->get_timings) {
 		struct omap_video_timings timings;
-		display->get_timings(display, &timings);
+		display->driver->get_timings(display, &timings);
 
 		/* pixclock in ps, the rest in pixclock */
 		var->pixclock = timings.pixel_clock != 0 ?
@@ -2029,14 +2029,14 @@
 	fbdev->bpp_overrides[fbdev->num_bpp_overrides].bpp = bpp;
 	++fbdev->num_bpp_overrides;
 
-	if (!display->check_timings || !display->set_timings)
+	if (!display->driver->check_timings || !display->driver->set_timings)
 		return -EINVAL;
 
-	r = display->check_timings(display, &timings);
+	r = display->driver->check_timings(display, &timings);
 	if (r)
 		return r;
 
-	display->set_timings(display, &timings);
+	display->driver->set_timings(display, &timings);
 
 	return 0;
 }