media: lirc_dev: remove min_timeout and max_timeout

There are no users of this functionality (ir-lirc-codec.c has its own
implementation and lirc_zilog.c doesn't use it) so remove it.

This only affects users of the lirc kapi, not rc-core drivers.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>