drm/rcar: call drm_put_dev directly in the ->remove hook

The magic dance drm_platform_exit does is actually a remnant of the
old legacy shadow attach support for platform devices. Modern modesetting
drm drivers shouldn't do this any more (and usb/pci devices actually don't
do this).

Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/rcar-du/rcar_du_drv.c

@@ -224,7 +224,9 @@ static int rcar_du_probe(struct platform_device *pdev)
 
 static int rcar_du_remove(struct platform_device *pdev)
 {
-	drm_platform_exit(&rcar_du_driver, pdev);
+	struct rcar_du_device *rcdu = platform_get_drvdata(pdev);
+
+	drm_put_dev(rcdu->ddev);
 
 	return 0;
 }