PID filters are moved to af9013 demod driver as those are property of
demod. As pid filters are now implemented correctly by demod driver,
we could enable pid filter support for possible slave demod too on
dual tuner configuration.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>