[media] DocBook media: fix wrong prototype

G_EDID is an RW ioctl, so the struct v4l2_edid isn't const.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/DocBook/media/v4l/vidioc-g-edid.xml

@@ -24,7 +24,7 @@
 	<funcdef>int <function>ioctl</function></funcdef>
 	<paramdef>int <parameter>fd</parameter></paramdef>
 	<paramdef>int <parameter>request</parameter></paramdef>
-	<paramdef>const struct v4l2_edid *<parameter>argp</parameter></paramdef>
+	<paramdef>struct v4l2_edid *<parameter>argp</parameter></paramdef>
       </funcprototype>
     </funcsynopsis>
   </refsynopsisdiv>