[media] v4l: subdev: Don't require core operations

There's no reason to require subdevices to implement the core
operations. Remove the check for non-NULL core operations when
initializing the subdev.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index d4d74f9..da16d2f 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -481,8 +481,7 @@
 					const struct v4l2_subdev_ops *ops)
 {
 	INIT_LIST_HEAD(&sd->list);
-	/* ops->core MUST be set */
-	BUG_ON(!ops || !ops->core);
+	BUG_ON(!ops);
 	sd->ops = ops;
 	sd->v4l2_dev = NULL;
 	sd->flags = 0;