This patch implements the "USB Gadget" API using the
"Goku-S" (TC86C001) full speed usb device controller.

It's passed testing with Gadget Zero, g_ether (full
CDC Ethernet support), gadgetfs, and most interestingly
Alan Stern's "File Storage Gadget" (FSG, talking to
Linux or Windows as a usb-storage device) to give the
halt processing a good workout.  Control-OUT works.
Tested mostly on x86, with reported success on MIPS.

As well as being directly useful with that hardware,
I think this is small and simple enough to be useful
as an example of how to write a USB controller driver.
(There will be many more controller drivers than gadget
drivers, I suspect ...)

Please merge this to the next 2.6 release that takes
new drivers.  Corresponding updates for kbuild and the
various gadget drivers will be coming (not in a flood).