BugLink: http://bugs.launchpad.net/bugs/1519623

A hcd roothub that supports HCD_USB31 is running at SuperSpeedPlus speed
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 5f9c3a66)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>