staging: octeon-usb: merge cvmx-usb into octeon-hcd

cvmx-usb module provided Cavium "OS abstraction layer" for USB
functionality. To make this driver a proper Linux driver, we need to
refactor this layer out. By making all the code internal to the HCD
driver makes this task easier.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>