[media] DocBook/dvbproperty.xml: Document the terrestrial delivery systems

Instead of repeating duplicate parameters to each delivery system,
just add a section for each specific delivery system, showing
what's applicable to each case. This helps userspace app developers
to know what DVB parameters are applicable to each delivery system.

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