[media] rc: nuvoton-cir: Add support for writing wakeup samples via sysfs filter callback

Nuvoton-cir utilizes the encoding capabilities of rc-core to convert
scancodes from user space to pulse/space format understood by the
underlying hardware.

Converted samples are then written to the wakeup fifo along with other
necessary configuration to enable wake up functionality.

Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: James Hogan <james@albanarts.com>
Cc: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>