All radio tuners in cx23885 driver using same address for radio and
tuner, so there is no need to probe it twice for same tuner and we can
use radio_type UNSET.

Be aware radio support in cx23885 is not yet committed, so this is only
minor fix for future support.
Signed-off-by: Miroslav Slugen <thunder.mmm@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>