[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/drivers/media/platform/davinci/vpbe_display.c b/drivers/media/platform/davinci/vpbe_display.c
index 9a05c81..e712d67 100644
--- a/drivers/media/platform/davinci/vpbe_display.c
+++ b/drivers/media/platform/davinci/vpbe_display.c
@@ -629,7 +629,7 @@
 }
 
 static int vpbe_display_s_crop(struct file *file, void *priv,
-			     struct v4l2_crop *crop)
+			     const struct v4l2_crop *crop)
 {
 	struct vpbe_fh *fh = file->private_data;
 	struct vpbe_layer *layer = fh->layer;