[media] rc-core: img-ir - leave the internals of rc_dev alone

Changing the protocol does not imply that the keymap changes.

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>