[coreboot] Prague meeting: Work on USB debug

[Nico Huber]

Hi folks,

I had first success with my pomona clip, today. Sadly, the mobo does
not have any UART,  so I'll finally have to switch to something more
advanced.  I've a high-speed ftdi usb adapter board that can be used
as USB debug device, but this will need some code changes along with
some refactoring.  I think, I'll focus on that during the hackathon.

It would be nice, to have some more usb debug devices available for
regression testing.

Nico