[media] DocBook: move DVB properties to happen earlier at the document

The DVBv5 API uses DVB properties as the main way to set the frontend
and collect statistics. Move the definition to happen earlier, in
order to reflect its importance.
Signed-off-by: NMauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/DocBook/media/dvb/frontend.xml

@@ -48,6 +48,8 @@ specification is available at
 
 &sub-frontend_read_status;
 
+&sub-dvbproperty;
+
 <section id="dvb-diseqc-master-cmd">
 <title>diseqc master command</title>
 
@@ -778,5 +780,3 @@ FE_TUNE_MODE_ONESHOT When set, this flag will disable any zigzagging or other "n
 
 &sub-frontend_legacy_api;
 </section>
-
-&sub-dvbproperty;