drm/exynos: Enable atomic modesetting feature

From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

Now that atomic modesetting is implemented for exynos enable the
DRIVER_ATOMIC flag on the driver's features.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NInki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_drm_drv.c

@@ -438,7 +438,8 @@ static const struct file_operations exynos_drm_driver_fops = {
 };
 
 static struct drm_driver exynos_drm_driver = {
-	.driver_features	= DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME,
+	.driver_features	= DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME
+				  | DRIVER_ATOMIC,
 	.load			= exynos_drm_load,
 	.unload			= exynos_drm_unload,
 	.suspend		= exynos_drm_suspend,