[media] omap_vout: fix crash if no driver for a display

omap_vout crashes on start if a corresponding driver is not loaded for a
display device.

This patch changes omap_vout init sequence to skip devices without a
driver.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/omap/omap_vout.c

@@ -2169,6 +2169,14 @@ static int __init omap_vout_probe(struct platform_device *pdev)
 	vid_dev->num_displays = 0;
 	for_each_dss_dev(dssdev) {
 		omap_dss_get_device(dssdev);
+
+		if (!dssdev->driver) {
+			dev_warn(&pdev->dev, "no driver for display: %s\n",
+					dssdev->name);
+			omap_dss_put_device(dssdev);
+			continue;
+		}
+
 		vid_dev->displays[vid_dev->num_displays++] = dssdev;
 	}