xhci: remove obsolete dequeue pointer moving code

xhci_find_new_dequeue_state() and xhci_queue_new_dequeue_state() are no
longer used afer introducing the move_dequeue_past_td() function.

also remove struct xhci_dequeue_state as its no longer used.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-26-mathias.nyman@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>