[media] DocBook: cleaup the notes about DTV properties

The notes there are somewhat confusing and assumes that the
reader would have read the DVBv3 way. This is not true anymore,
as the DVBv3 is now on a separate section that is marked as
deprecated.

So, cleanup the notes.

While here, add a note about using libdvbv5, instead of using
the DVBv5 API directly.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/DocBook/media/dvb/dvbproperty.xml

@@ -13,8 +13,14 @@
     Also, the union didn't have any space left to be expanded without breaking
     userspace. So, the decision was to deprecate the legacy union/struct based
     approach, in favor of a properties set approach.</para>
-<para>By using a properties set, it is now possible to extend and support any
-    digital TV without needing to redesign the API</para>
+
+<para>NOTE: on Linux DVB API version 3, setting a frontend were done via
+    <link linkend="dvb-frontend-parameters">struct  <constant>dvb_frontend_parameters</constant></link>.
+    This got replaced on version 5 (also called "S2API", as this API were
+    added originally_enabled to provide support for DVB-S2), because the old
+    API has a very limited support to new standards and new hardware. This
+    section describes the new and recommended way to set the frontend, with
+    suppports all digital TV delivery systems.</para>
 
 <para>Example: with the properties based approach, in order to set the tuner
     to a DVB-C channel at 651 kHz, modulated with 256-QAM, FEC 3/4 and symbol
@@ -67,13 +73,13 @@ int main(void)
 	return 0;
 }
 </programlisting>
-<para>NOTE: This section describes the DVB version 5 extension of the DVB-API,
-also called "S2API", as this API were added to provide support for DVB-S2. It
-was designed to be able to replace the old frontend API. Yet, the DISEQC and
-the capability ioctls weren't implemented yet via the new way.</para>
-<para>The typical usage for the <constant>FE_GET_PROPERTY/FE_SET_PROPERTY</constant>
-API is to replace the ioctl's were the <link linkend="dvb-frontend-parameters">
-struct <constant>dvb_frontend_parameters</constant></link> were used.</para>
+
+<para>NOTE: While it is possible to directly call the Kernel code like the
+    above example, it is strongly recommended to use
+    <ulink url="http://linuxtv.org/docs/libdvbv5/index.html">libdvbv5</ulink>,
+    as it provides abstraction to work with the supported digital TV standards
+    and provides methods for usual operations like program scanning and to
+    read/write channel descriptor files.</para>
 
 <section id="dtv-stats">
 <title>struct <structname>dtv_stats</structname></title>