wusb: hub code recognizes wusb ports

This patch enables the USB stack to recognize WUSB devices (from a
WUSB HCD) and assigns them the proper speed setting
(USB_SPEED_VARIABLE).

1. Introduce usb_hcd->wireless to mark a host controller instance as
   being wireless, and thus having wireless 'fake' ports. 

   [discarded previous model of using a reserved bit in the port_stat
   struct to do this; thanks to Alan Stern for indicating the
   proper way to do it].

2. Introduce hub.c:hub_is_wusb() that tests if a hub is a WUSB root
   hub (WUSB doesn't have non-root hubs).

New code being pushed to linuxuwb.org requires this patch to connect WUSB
devices.

Signed-off-by: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>