V4L/DVB (12393): cx88: fix regression in tuning for Geniatech X8000 MT

The introduction of the zl10353 i2c gate control broke support for the
Geniatech board (which is not behind an i2 gate).  Add the needed parameter.

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