[media] saa7134: Remove legacy IR decoding logic inside the module

The only IR left still using the old raw decoders on saa7134 is ENCORE
FM 5.3. As it is now using the standard rc-core raw decoders, lots
of old code can be removed from saa7134.

Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>