usb: typec: mux: Find the muxes by also matching against the device node

When the connections are defined in firmware, struct
device_connection will have the fwnode member pointing to
the device node (struct fwnode_handle) of the requested
device, and the endpoint will not be used at all in that
case.

Acked-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>