Merge remote-tracking branch 'kraxel/usb.80' into staging

Merge remote-tracking branch 'kraxel/usb.80' into staging

# By Gerd Hoffmann (6) and Hans de Goede (1)
# Via Gerd Hoffmann
* kraxel/usb.80:
  use libusb for usb-host
  xhci: fix address device
  xhci: use slotid as device address
  xhci: fix portsc writes
  xhci: add xhci_cap_write
  xhci: remove leftover debug printf
  usb-serial: Remove double call to qemu_chr_add_handlers( NULL )

Message-id: 1366107190-30853-1-git-send-email-kraxel@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>