buzzer driver

[Sylvain Munaut]

Hi,

> Hi all, my name is Jose Pereira, and i'm very interested in helping you with
> some code! I've wrote the buzzer driver for calypso, not so sure if will
> help you of anything, but was just for experimenting :)

Thanks for this, it took us quite a bit of time to merge it, but now
it's done :)

We were looking how to signal debug some stuff and the beeper sounded
like a good option. (no pun intended :p)

Cheers,

    Sylvain