style(xilinx): fix AMD copyright format

There is missing comma in copyright line. It is better to have all
Copyrights align to the same style that's why fix it.

Change-Id: Ifc04b474e1a172a7243b073d944007cf17d76e87
Signed-off-by: Michal Simek <michal.simek@amd.com>
diff --git a/plat/xilinx/zynqmp/pm_service/zynqmp_pm_svc_main.h b/plat/xilinx/zynqmp/pm_service/zynqmp_pm_svc_main.h
index 9eda90b..bef72b6 100644
--- a/plat/xilinx/zynqmp/pm_service/zynqmp_pm_svc_main.h
+++ b/plat/xilinx/zynqmp/pm_service/zynqmp_pm_svc_main.h
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2013-2020, Arm Limited and Contributors. All rights reserved.
- * Copyright (c) 2023, Advanced Micro Devices Inc. All rights reserved.
+ * Copyright (c) 2023, Advanced Micro Devices, Inc. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */