media: rc: meson-ir: add timeout on idle

Meson doesn't seem to be able to generate timeout events in hardware. So
install a software timer to generate the timeout events required by the
decoders to prevent "ghost keypresses".

Reported-by: Matthias Reichl <hias@horus.com>
Tested-by: Matthias Reichl <hias@horus.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>