clk: sunxi-ng: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style
in header files related to Clock Drivers for Allwinner SoCs.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/sunxi-ng/ccu-sun50i-h6.h

-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright 2016 Icenowy Zheng <icenowy@aosc.io>
  */

drivers/clk/sunxi-ng/ccu-suniv-f1c100s.h

-/* SPDX-License-Identifier: GPL-2.0+
- *
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
  * Copyright 2017 Icenowy Zheng <icenowy@aosc.io>
  *
  */