[media] rc-core: fix protocol_change regression in ir_raw_event_register

[media] rc-core: fix protocol_change regression in ir_raw_event_register

IR receiver using nuvoton-cir and lirc required additional configuration
steps after upgrade from kernel 3.16 to 3.17-rcX. Bisected regression to
commit c097ac79903c143773b7b8e44fd53e64475f9af3 ("[media] rc-core:
simplify sysfs code").

The regression comes from adding function change_protocol in ir-raw.c.
It changes behaviour so that only the protocol enabled by driver's
map_name will be active after registration. This breaks user space
behaviour, lirc does not get key press signals anymore.

Enable lirc protocol by default for ir raw decoders to restore original
behaviour.

Cc: stable@vger.kernel.org # for v3.17
Signed-off-by: Tomas Melin <tomas.melin@iki.fi>
Acked-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>