drm/omap: set DRIVER_ATOMIC for omapdrm

omapdrm supports atomic modesetting, and it seems to work ok. So let's
set the flag to enable the atomic modesetting API support.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -832,7 +832,8 @@ static const struct file_operations omapdriver_fops = {
 };
 
 static struct drm_driver omap_drm_driver = {
-	.driver_features = DRIVER_MODESET | DRIVER_GEM  | DRIVER_PRIME,
+	.driver_features = DRIVER_MODESET | DRIVER_GEM  | DRIVER_PRIME |
+		DRIVER_ATOMIC,
 	.load = dev_load,
 	.unload = dev_unload,
 	.open = dev_open,