[media] DocBook: Add tuner subdev at documentation

Now that we've added MEDIA_ENT_T_V4L2_SUBDEV_TUNER at the API,
document it.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/DocBook/media/v4l/media-ioc-enum-entities.xml

@@ -226,6 +226,10 @@
 	    it in some digital video standard, with appropriate embedded timing
 	    signals.</entry>
 	  </row>
+	  <row>
+	    <entry><constant>MEDIA_ENT_T_V4L2_SUBDEV_TUNER</constant></entry>
+	    <entry>TV and/or radio tuner</entry>
+	  </row>
 	</tbody>
       </tgroup>
     </table>

Documentation/DocBook/media/v4l/v4l2.xml

@@ -157,6 +157,7 @@ applications. -->
 	<date>2015-02-13</date>
 	<authorinitials>mcc</authorinitials>
 	<revremark>Fix documentation for media controller device nodes and add support for DVB device nodes.
+Add support for Tuner sub-device.
 	</revremark>
       </revision>
       <revision>