Merge remote-tracking branch 'remotes/kraxel/tags/usb-20181001-pull-request' into...

Merge remote-tracking branch 'remotes/kraxel/tags/usb-20181001-pull-request' into staging

usb: fixes for mtp, hub and ohci.

# gpg: Signature made Mon 01 Oct 2018 10:28:36 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# 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/usb-20181001-pull-request:
  ohci: set effectively usb frame rate to 1kHz
  usb-hub: clear suspend on detach
  usb-mtp: reset ObjectInfo dataset size on cleanup
  doc: replace x-root with rootdir for usb-mtp
  usb-mtp: fix error conditions for write operation

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