V4L/DVB (4016): Cx88-blackbird: add support for ProLink Pixelview Playtv@P7000

- Add support for ProLink Pixelview Playtv@P7000
Raw video and MPEG encoded video confirmed to work properly.
SVideo, Composite and FM inputs are untested - disabled for now.

Signed-off-by: Angelo Marconi <am@massalombarda.net>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>