MLBEDSW-7100: Update mlw_codec copyright years

Some copyright years of files in the mlw_codec had not been updated
during changes in late 2022.

Signed-off-by: Rickard Bolin <rickard.bolin@arm.com>
Change-Id: Iebab154127e5868202a805aff0125154ac1d3beb
diff --git a/ethosu/mlw_codec/mlw_main.c b/ethosu/mlw_codec/mlw_main.c
index a3a38be..0e25036 100644
--- a/ethosu/mlw_codec/mlw_main.c
+++ b/ethosu/mlw_codec/mlw_main.c
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: Copyright 2020 Arm Limited and/or its affiliates <open-source-office@arm.com>
+ * SPDX-FileCopyrightText: Copyright 2020, 2022 Arm Limited and/or its affiliates <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  *