[media] tuner_xc2028: Allow selection of the frequency adjustment code for XC3028

This device is not using the proper demod IF. Instead of using the
IF macro, it is specifying a IF frequency. This doesn't work, as xc3028
needs to load an specific SCODE for the tuner. In this case, there's
no IF table for 5 MHz.

Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>