New protocol decoder: maple_bus

If you're into game consoles you might want to check out the latest protocol decoder in libsigrokdecode: maple_bus.

This decodes the Maple bus, the protocol that peripherals of the Sega Dreamcast (controllers, memory cards, others) use.

The protocol decoder was contributed by Marcus Comstedt, thanks a lot!

Marcus also has documented both the low-level Maple bus wire protocol as well as the higher level frame format and the meaning of the bits and bytes involved in great detail.

As usual, there's also an example file in sigrok-dumps as well as a test-case in our sigrok-test repo to go along with it.