[media] DocBook/Makefile: Remove osd.h header

The av7110 uses an OSD API. Such API is not documented at all. Also,
the osd.h API uses camelCase and some other weird stuff. Also, dvb-core
doesn't recognize it.

I don't see any good reason why we should document it. It seems better
to just let it as-is. If ever needed, it is probably better to write
a different API for dvb-core.

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

Documentation/DocBook/media/dvb/dvbapi.xml

@@ -134,10 +134,6 @@ Added ISDB-T test originally written by Patrick Boettcher
     <title>DVB Network Header File</title>
     &sub-net-h;
   </appendix>
-  <appendix id="osd_h">
-    <title>DVB OSD Header File</title>
-    &sub-osd-h;
-  </appendix>
   <appendix id="video_h">
     <title>DVB Video Header File</title>
     &sub-video-h;