Update Doxygen file blocks to remove copyright and license information
diff --git a/include/mbedtls/timing.h b/include/mbedtls/timing.h
index bfb8579..2c497bf 100644
--- a/include/mbedtls/timing.h
+++ b/include/mbedtls/timing.h
@@ -2,7 +2,8 @@
  * \file timing.h
  *
  * \brief Portable interface to timeouts and to the CPU cycle counter
- *
+ */
+/*
  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *