USB interfaces reorganization
The most important change is that getting USB address of a device
is an operation of generic USB interface, not USB-HC interface.
That is needed for proper functionality of a MID driver.
Also added sample implementation of USB interface operations as is
needed by most drivers (sample does not mean unfunctional or partially
implemented here).
They are stored in libusb/ddfiface.h
Updated UHCI, UHCI-RH, hub, VHC drivers to use these sample
implementations.
Updated libusb device recognition routines to route get_address requests
through USB interface.
