media: rc: rename RC_TYPE_* to RC_PROTO_* and RC_BIT_* to RC_PROTO_BIT_*

RC_TYPE is confusing and it's just the protocol. So rename it.

Suggested-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Sean Young <sean@mess.org>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>