V4L/DVB: ir-core: Rename sysfs protocols nomenclature to rc-5 and rc-6

V4L/DVB: ir-core: Rename sysfs protocols nomenclature to rc-5 and rc-6

While rc-5 and rc-6 protocols are generally abreviated as "rc5" and "rc6",
previous sysfs nodes uses rc-5 and rc-6 for the Philips protocols. This is
consistent with the protocol nomenclature given by the original Philips
spec: "Remote control system RC-5" (doc. Nr. 9398 706 23011).
Also, rc5 is the name of a widely known cryptography protocol.

So, the better is to keep referring to those protocols as "rc-5" and "rc-6".

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>