[media] saa7134: fix IR handling for HVR-1110

Return the complete RC-5 code, instead of just the 8 least significant
bits.

Reported-by: Dorozel Csaba <mrjuuzer@upcmail.hu>
Tested-by: Dorozel Csaba <mrjuuzer@upcmail.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>