Staging: comedi: s626: use subvendor:subdevice ids for SAA7146 board

The current s626 comedi driver in staging conflicts with philips SAA7146
media/dvb based cards, because it claims the same vendor:device pci id
for all subdevice/subvendor ids. What happens is that for people that have a
philips SAA7146 media/dvb based card, s626 if available gets loaded by udev
and makes system freeze (https://qa.mandriva.com/show_bug.cgi?id=51445).

The s626 driver shouldn't claim all 1131:7146 devices. Fix this by
specifying specific known subvendor:subdevice ids in its pci id table
list.

Also s626_attach is modified to use now pci_get_subsys instead of
pci_get_device as reported by Ian Abbott, and now we loop over pci id
table entries in case more ids are added in the future.

Reference: http://lkml.org/lkml/2009/6/16/552

Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>