thunderbolt: Set lane bonding bit only for downstream port

Fix the lane bonding procedure to follow the steps described in USB4
Connection Manager guide. Hence, set the lane bonding bit only for
downstream port. This is needed for certain ASMedia device, otherwise
lane bonding fails and the device disconnects.

Cc: stable@vger.kernel.org
Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/thunderbolt/switch.c

@@ -1143,7 +1143,7 @@ int tb_port_lane_bonding_enable(struct tb_port *port)
 	 * Only set bonding if the link was not already bonded. This
 	 * avoids the lane adapter to re-enter bonding state.
 	 */
-	if (width == TB_LINK_WIDTH_SINGLE) {
+	if (width == TB_LINK_WIDTH_SINGLE && !tb_is_upstream_port(port)) {
 		ret = tb_port_set_lane_bonding(port, true);
 		if (ret)
 			goto err_lane1;