mmc: dw_mmc-bluefield: : Fix the license information

The SPDX license identifier and the boiler plate text are
contradicting. Only the SPDX license identifier is needed. The
other one is removed.

Fixes: 86958dcc ("mmc: dw_mmc-bluefield: Add driver extension")
Cc: stable@vger.kernel.org
Reviewed-by: David Woods <dwoods@mellanox.com>
Signed-off-by: Liming Sun <lsun@mellanox.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/dw_mmc-bluefield.c

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2018 Mellanox Technologies.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
  */
 
 #include <linux/bitfield.h>