[media] rc: img-ir: add scancode requests to a struct

The information being requested of hardware decode callbacks through
the img-ir-hw scancode API is mounting up, so combine it into a struct
which can be passed in with a single pointer rather than multiple
pointer arguments. This allows it to be extended more easily without
touching all the hardware decode callbacks.

Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>