[media] cx231xx: properly use the right tuner i2c address

The driver has a field to indicate what bus is used by tuner and
by demod. However, this field were never used. On Pixelview,
it uses I2C 2 for tuner, instead of I2C 1.

	drivers/media/video/cx231xx/cx231xx-cards.c

Acked-by: Sri Deevi <Srinivasa.Deevi@conexant.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>