[media] cx231xx: remove board specific check for Colibri configuration

The cx231xx_set_Colibri_For_LowIF() function is only ever called if the tuner
has a DIF (see vidioc_s_frequency() in cx231xx-video.c).  Hence, we do not
need to do a board specific check in this function.

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