[media] redrat3: improve compat with lirc userspace decode

This is admittedly a bit of a hack, but if we change our timeout value
to something longer and fudge our synthesized trailing space sample
based on the initial pulse sample, rc-core decode continues to work just
fine with both rc-6 and rc-5, and now lirc userspace decode shows proper
repeats for both of those protocols as well. Also tested NEC
successfully with both decode options.

We do still need a reset timer callback using the hardware's timeout
value to make sure we actually process samples correctly, regardless of
our somewhat hacky timeout and synthesized trailer above.

This also adds a missing del_timer_sync call to the module unload path.

CC: Chris Dodge <chris@redrat.co.uk>
CC: Andrew Vincer <andrew.vincer@redrat.co.uk>
CC: Stephen Cox <scox_nz@yahoo.com>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>