V4L/DVB (6037): Updated GenPix USB driver

There are now 4 different versions of the GENPIX USB adapter.  The 
newest 'Skywalker' models are fully self-contained, and need no 
additional hardware to be used.  A very reliable DVB-S card even without 
using any of the alternate modulatations (which this kernel module does 
not currently support)

The following patch adds support for all 4 versions of the genpix
adapter (www.genpix-electronics.com).

Signed-off-by: Alan Nisota <alannisota@gmail.com>
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>