Merge remote-tracking branch 'remotes/kraxel/tags/pull-usb-20161012-1' into staging

Merge remote-tracking branch 'remotes/kraxel/tags/pull-usb-20161012-1' into staging

various usb bugfixes
some xhci cleanups

# gpg: Signature made Wed 12 Oct 2016 13:38:27 BST
# gpg:                using RSA key 0x4CB6D8EED3E87138
# 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>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/pull-usb-20161012-1:
  usb-redir: allocate buffers before waking up the host adapter
  usb: Fix incorrect default DMA offset.
  usb: fix serial generator
  xhci: make xhci_epid_to_usbep accept XHCIEPContext
  xhci: drop XHCITransfer->{slotid,epid}
  xhci: add & use xhci_kick_epctx()
  xhci: drop XHCITransfer->xhci
  xhci: use linked list for transfers
  xhci: drop unused comp_xfer field
  xhci: decouple EV_QUEUE from TD_QUEUE
  xhci: limit the number of link trbs we are willing to process

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