USB: Add USB 3.0 roothub support to USB core.

Add USB 3.0 root hub descriptors.  This is a kludge because I reused the old
USB 2.0 descriptors, instead of using the new USB 3.0 hub descriptors with
endpoint companion descriptors and other descriptors.  I did this because I
wasn't ready to add USB 3.0 hub changes to khubd.  For now, a USB 3.0 roothub
looks like a USB 2.0 roothub, with a higher speed.

USB 3.0 hubs have no transaction translator (TT).

Make USB core debugging handle super speed ports.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>