[media] DocBook/dvbproperty.xml: Document the remaining S2API parameters

There were lots of DVB S2API parameters that were never documented.
Let's add a definition for all of them, based on what's currently
used inside the core and the drivers.

The description here is not complete nor perfect, so patches
improving it are welcome.

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