usb-hcd-xhci: Update endpoint context dequeue pointer for streams too

usb-hcd-xhci: Update endpoint context dequeue pointer for streams too

With streams the endpoint context dequeue pointer should point to the
dequeue value for the currently active stream.

At least Linux guests expect it to point to value set by an set_ep_dequeue
upon completion of the set_ep_dequeue (before kicking the ep).

Otherwise the Linux kernel will complain (and things won't work):

xhci_hcd 0000:00:05.0: Mismatch between completed Set TR Deq Ptr command & xHCI internal state.
xhci_hcd 0000:00:05.0: ep deq seg = ffff8800366f0880, deq ptr = ffff8800366ec010

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>