[media] ir-core: remove remaining users of the ir-functions keyhandlers

This patch removes the remaining usages of the ir_input_nokey() and
ir_input_keydown() functions provided by drivers/media/IR/ir-functions.c
by using the corresponding functionality in ir-core instead.

Signed-off-by: David Härdeman <david@hardeman.nu>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>