Merge remote-tracking branch 'remotes/kraxel/tags/pull-usb-20141112-1' into staging

usb bugfixes for 2.2

# gpg: Signature made Wed 12 Nov 2014 14:35:09 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-usb-20141112-1:
  usb-host: fix usb_host_speed_compat tyops
  xhci: add sanity checks to xhci_lookup_uport
  Provide the missing LIBUSB_LOG_LEVEL_* for older libusb or FreeBSD. Providing just the needed value as a defined.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>