V4L/DVB (7084): saa7134: add support for the Medion / Creatix CTX948 card

This adds support for analog inputs and DVB-T.
Good sensitivity for DVB-T currently needs to use analog TV first.
DVB-S support is not yet completed, but is on the way.

Signed-off-by: Hermann Pitton <hermann-pitton@arcor.de>
Signed-off-by: Hartmut Hackmann <hartmut.hackmann@t-online.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>