Adds an structure to ir_input_register to contain IR device characteristics,
like supported protocols and a callback to handle protocol event changes.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Add sysfs skeleton to export remote controller information via
/sys/class/irrcv.

For now, the code doesn't do much. It just exports an attribute that
is meant to  report and control the IR protocol used by the keytable.
However, the callbacks for this new attribute weren't set yet.

Also, it lacks symlinks to the used event interface.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Now, ir_input_free does more than just freeing the keytab. Better to
rename it as ir_input_unregister.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Move non-V4L specific stuff from ir-functions ir_input_init() into
a new function to register ir devices: ir_input_register().
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

Split the ir-common into two separate modules:
	- ir-core: it is the IR-independent functions;
	- ir-common: has the common part used by V4L drivers.
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>