V4L/DVB: ir: use a real device instead of a virtual class

Change the ir-sysfs approach to create irrcv0 as a device, instead of
using class_dev. Also, change the way input is registered, in order
to make its parent to be the irrcv device.

Due to this change, now the event device is created under
/sys/class/ir/irrcv class:

/sys/class/irrcv/irrcv0/
|-- current_protocol
|-- device -> ../../../1-3
|-- input9
|   |-- capabilities
|   |   |-- abs
...

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>