[media] omap3isp: Default link validation for ccp2, csi2, preview and resizer

Use default link validation for ccp2, csi2, preview and resizer. On ccp2,
csi2 and ccdc we also collect information on external subdevs as one may be
connected to those entities.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/omap3isp/isppreview.c b/drivers/media/video/omap3isp/isppreview.c
index cbc8870..8a4935e 100644
--- a/drivers/media/video/omap3isp/isppreview.c
+++ b/drivers/media/video/omap3isp/isppreview.c
@@ -2217,6 +2217,7 @@
 /* media operations */
 static const struct media_entity_operations preview_media_ops = {
 	.link_setup = preview_link_setup,
+	.link_validate = v4l2_subdev_link_validate,
 };
 
 void omap3isp_preview_unregister_entities(struct isp_prev_device *prev)