usb: typec: Remove retimers properly

Retimer device class is left dangling when the typec module
is unloaded. Attempts to reload the module failed with warning:

        "sysfs: cannot create duplicate filename '/class/retimer'"

Fixing the issue by unregistering the class properly.

Fixes: ddaf8d9 ("usb: typec: Add support for retimers")
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20220825140411.10743-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/class.c

@@ -2346,6 +2346,7 @@ static void __exit typec_exit(void)
 	ida_destroy(&typec_index_ida);
 	bus_unregister(&typec_bus);
 	class_unregister(&typec_mux_class);
+	class_unregister(&retimer_class);
 }
 module_exit(typec_exit);