[media] fc0012: use struct for driver config

I need even more configuration options and overloading dvb_attach()
for all those sounds quite stupid. Due to that switch struct and make
room for new options.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Acked-by: Hans-Frieder Vogt <hfvogt@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>