dma-mapping: benchmark: use the correct HiSilicon copyright

s/Hisilicon/HiSilicon/g.
It should use capital S, according to
https://www.hisilicon.com/en/terms-of-use.
Signed-off-by: Hao Fang <fanghao11@huawei.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

kernel/dma/map_benchmark.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (C) 2020 Hisilicon Limited.
+ * Copyright (C) 2020 HiSilicon Limited.
  */
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

tools/testing/selftests/dma/dma_map_benchmark.c

 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (C) 2020 Hisilicon Limited.
+ * Copyright (C) 2020 HiSilicon Limited.
  */
 
 #include <fcntl.h>