[media] DocBook/media/v4l: update version number

The version number was still 3.9: update to 3.10.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Documentation/DocBook/media/v4l/v4l2.xml

@@ -493,7 +493,7 @@ and discussions on the V4L mailing list.</revremark>
 </partinfo>
 
 <title>Video for Linux Two API Specification</title>
- <subtitle>Revision 3.9</subtitle>
+ <subtitle>Revision 3.10</subtitle>
 
   <chapter id="common">
     &sub-common;