Patch to support DvbWorld DW2104 device modifications
with STV0903 and DS3000 demods as well as TeVii S660 and Prof 1100
Also replace some magic numbers with meaningfull variables.
Signed-off-by: Igor M. Liplianin <liplianin@me.by>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>