[media] v4l2: make vidioc_s_crop const

Write-only ioctls should have a const argument in the ioctl op.
Do this conversion for vidioc_s_crop.
Adding const for write-only ioctls was decided during the 2012 Media Workshop.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index e698f2c..2ecd737 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -286,7 +286,7 @@
 	int (*s_stream)(struct v4l2_subdev *sd, int enable);
 	int (*cropcap)(struct v4l2_subdev *sd, struct v4l2_cropcap *cc);
 	int (*g_crop)(struct v4l2_subdev *sd, struct v4l2_crop *crop);
-	int (*s_crop)(struct v4l2_subdev *sd, struct v4l2_crop *crop);
+	int (*s_crop)(struct v4l2_subdev *sd, const struct v4l2_crop *crop);
 	int (*g_parm)(struct v4l2_subdev *sd, struct v4l2_streamparm *param);
 	int (*s_parm)(struct v4l2_subdev *sd, struct v4l2_streamparm *param);
 	int (*g_frame_interval)(struct v4l2_subdev *sd,