[media] v4l2: make vidioc_s_freq_hw_seek const

Write-only ioctls should have a const argument in the ioctl op.
Do this conversion for vidioc_s_freq_hw_seek.
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-ioctl.h b/include/media/v4l2-ioctl.h
index 21f6245..865f95d 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -233,7 +233,7 @@
 	int (*vidioc_log_status)       (struct file *file, void *fh);
 
 	int (*vidioc_s_hw_freq_seek)   (struct file *file, void *fh,
-					struct v4l2_hw_freq_seek *a);
+					const struct v4l2_hw_freq_seek *a);
 
 	/* Debugging ioctls */
 #ifdef CONFIG_VIDEO_ADV_DEBUG