Bluetooth: hci_ll: Use new hci_uart_unregister_device() function

Convert hci_ll to use hci_uart_unregister_device().

This simplifies the _remove() handler as well as fixes a
potential race condition on unload.
Signed-off-by: NIan Molton <ian@mnementh.co.uk>
Reviewed-by: NSebastian Reichel <sebastian.reichel@collabor.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/hci_ll.c

@@ -742,14 +742,8 @@ static int hci_ti_probe(struct serdev_device *serdev)
 static void hci_ti_remove(struct serdev_device *serdev)
 {
 	struct ll_device *lldev = serdev_device_get_drvdata(serdev);
-	struct hci_uart *hu = &lldev->hu;
-	struct hci_dev *hdev = hu->hdev;
 
-	cancel_work_sync(&hu->write_work);
-
-	hci_unregister_dev(hdev);
-	hci_free_dev(hdev);
-	hu->proto->close(hu);
+	hci_uart_unregister_device(&lldev->hu);
 }
 
 static const struct of_device_id hci_ti_of_match[] = {