[media] cx231xx: remove board specific initialization

There is no need for a switch statement here.  Use the contents of the board
profile to dictate the tuner driver and i2c address.  Eventually if a board
ever comes around which has a different i2c bus than #1, well that should be a
field in the board profile as well.

Signed-off-by: Devin Heitmueller <dheitmueller@hauppauge.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>