feat(xilinx): sync copyright format

Use the same format in all files 's/Copyright (C)/Copyright (c)/g'.

Change-Id: I0e200eb135e7369d0e6b3b694acd406ec10ca9e7
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/plat/xilinx/versal_net/versal_net_ipi.c b/plat/xilinx/versal_net/versal_net_ipi.c
index 26ded89..cf897e3 100644
--- a/plat/xilinx/versal_net/versal_net_ipi.c
+++ b/plat/xilinx/versal_net/versal_net_ipi.c
@@ -1,6 +1,6 @@
 /*
- * Copyright (C) 2022, Xilinx, Inc. All rights reserved.
- * Copyright (C) 2022, Advanced Micro Devices, Inc. All rights reserved.
+ * Copyright (c) 2022, Xilinx, Inc. All rights reserved.
+ * Copyright (c) 2022, Advanced Micro Devices, Inc. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */