usb: cdns3: change "cdsn3" to"cdns3"

And delete cdsn3_hw_role_state_machine declare which doesn't
be needed.

Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>