USB host controller diffs

[Nathan Binkert <binkertn@umich.edu>]

I've imported a bunch of host controller fixes and support for USB 2.0
from NetBSD.  I would appreciate it if as many people as possible would
test this out, and report their successes/failures to me.  (With dmesg)

Testing includes testing whatever devices you have, in addition to
plugging in and removing devices to make sure that things work properly.

I would especially like to see tests on non i386 architectures.

The diff is at http://piton.chaotic.net/diff/usb.hc.diff

Thanks,

  Nathan