staging: hikey9xx: hi6421-spmi-pmic: update copyright

Remove the GPL boilerplate, as SPDX tag already points to the
license terms and add a new copyright for Huawei.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/18b36d01c04519d84912140b6c40c1bd1f75a3a8.1611212783.git.mchehab+huawei@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/hikey9xx/hi6421-spmi-pmic.c

 // SPDX-License-Identifier: GPL-2.0
-/*
- * Device driver for regulators in HISI PMIC IC
- *
- * Copyright (c) 2013 Linaro Ltd.
- * Copyright (c) 2011 Hisilicon.
- *
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
+//
+// Device driver for regulators in HISI PMIC IC
+//
+// Copyright (c) 2013 Linaro Ltd.
+// Copyright (c) 2011 Hisilicon.
+//
+// Copyright (c) 2020-2021 Huawei Technologies Co., Ltd
 
 #include <linux/delay.h>
 #include <linux/device.h>