Filtering given PIDs from the transport stream is done by the
DVB USB bridge. It is highly possible there is limitations what
kind of stream DVB USB bridge can PID filter, but it still does
not make sense to define filters for each frontend as frontend
could offer different stream types for different standards.

Likely new way is to enable / disable PID filters are needed to
make decision at runtime (callback). PID filters are quite legacy
stuff as those are aimed cut stream smaller to fit for the USB1.1...
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>