usb: usb3.0 ch9 definitions

Adding SuperSpeed usb definitions as defined by ch9 of the USB3.0 spec.
This patch is a preparation for adding SuperSpeed support to the gadget
framework.

Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>