Update license headers

Update all license headers to the correct years

Change-Id: I638a854b39b4afe8db6a4a76ca6dcb89c126e3c1
diff --git a/applications/message_process/include/message_process.hpp b/applications/message_process/include/message_process.hpp
index cae1e35..b10d52f 100644
--- a/applications/message_process/include/message_process.hpp
+++ b/applications/message_process/include/message_process.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020 Arm Limited. All rights reserved.
+ * Copyright (c) 2020-2021 Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: Apache-2.0
  *