xhci: dbc: remove endpoint pointers from dbc_port structure

dbctty no longer needs references directly to dbc endpoints,
so remove them

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200723144530.9992-24-mathias.nyman@linux.intel.com


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