OMAP: DSS2: move enable/get_te()

Move enable/get_te() 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-ioctl.c b/drivers/video/omap2/omapfb/omapfb-ioctl.c
index 6deabb9..cb2e343 100644
--- a/drivers/video/omap2/omapfb/omapfb-ioctl.c
+++ b/drivers/video/omap2/omapfb/omapfb-ioctl.c
@@ -732,12 +732,13 @@
 			break;
 		}
 
-		if (!display->enable_te) {
+		if (!display->driver->enable_te) {
 			r = -ENODEV;
 			break;
 		}
 
-		r = display->enable_te(display, !!p.tearsync_info.enabled);
+		r = display->driver->enable_te(display,
+				!!p.tearsync_info.enabled);
 
 		break;
 	}