drm/tilcdc: Convert drm_atomic_helper_suspend/resume()

convert drm_atomic_helper_suspend/resume() to use
drm_mode_config_helper_suspend/resume().

saved_state in tilcdc_drm_private will not be used
anymore, so it can be removed.

Signed-off-by: Ajit Negi <ajitn.linux@gmail.com>
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Tested-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Jyri Sarha <jsarha@ti.com>
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 0fb300d..33e5332 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -554,29 +554,23 @@ static struct drm_driver tilcdc_driver = {
 static int tilcdc_pm_suspend(struct device *dev)
 {
 	struct drm_device *ddev = dev_get_drvdata(dev);
-	struct tilcdc_drm_private *priv = ddev->dev_private;
+	int ret = 0;
 
-	priv->saved_state = drm_atomic_helper_suspend(ddev);
+	ret = drm_mode_config_helper_suspend(ddev);
 
 	/* Select sleep pin state */
 	pinctrl_pm_select_sleep_state(dev);
 
-	return 0;
+	return ret;
 }
 
 static int tilcdc_pm_resume(struct device *dev)
 {
 	struct drm_device *ddev = dev_get_drvdata(dev);
-	struct tilcdc_drm_private *priv = ddev->dev_private;
-	int ret = 0;
 
 	/* Select default pin state */
 	pinctrl_pm_select_default_state(dev);
-
-	if (priv->saved_state)
-		ret = drm_atomic_helper_resume(ddev, priv->saved_state);
-
-	return ret;
+	return  drm_mode_config_helper_resume(ddev);
 }
 #endif