The NEC scancode composing and protocol type detection in
ir_nec_decode() is generic enough to be a shared function.  Let's create
an inline function in rc-core.h, so that other remote control drivers
can reuse this function to save some code.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NSean Young <sean@mess.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>