V4L/DVB (4882): budget-ci IR: make debounce logic conditional

Change the debounce logic so that it is not used at all unless the
debounce parameter has been set. This makes for a much "snappier" remote
for most users as there is no timeout to wait for (the debounce logic has
a 350ms timer for the next repeat, but with the RC5 protocol, one event
per ~110ms is possible)

Signed-off-by: David Hardeman <david@hardeman.nu>
Signed-off-by: Andrew de Quincey <adq_dvb@lidskialf.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>