[media] rc: add wakeup_protocols sysfs file

Add a wakeup_protocols sysfs file which controls the new
rc_dev::enabled_protocols[RC_FILTER_WAKEUP], which is the mask of
protocols that are used for the wakeup filter.

A new RC driver callback change_wakeup_protocol() is called to change
the wakeup protocol mask.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reviewed-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>