ASoC: xlnx: change license header format style

Changed License header from C to C++ style comment block.
Signed-off-by: Maruthi Srinivas Bayyavarapu <maruthi.srinivas.bayyavarapu@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/xilinx/xlnx_i2s.c

 // SPDX-License-Identifier: GPL-2.0
-/*
- * Xilinx ASoC I2S audio support
- *
- * Copyright (C) 2018 Xilinx, Inc.
- *
- * Author: Praveen Vuppala <praveenv@xilinx.com>
- * Author: Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>
- */
+//
+// Xilinx ASoC I2S audio support
+//
+// Copyright (C) 2018 Xilinx, Inc.
+//
+// Author: Praveen Vuppala <praveenv@xilinx.com>
+// Author: Maruthi Srinivas Bayyavarapu <maruthis@xilinx.com>
 
 #include <linux/io.h>
 #include <linux/module.h>