Update headers

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/scripts/generate_errors.pl b/scripts/generate_errors.pl
index e950bc5..bb5cb9f 100755
--- a/scripts/generate_errors.pl
+++ b/scripts/generate_errors.pl
@@ -6,19 +6,7 @@
 # or generate_errors.pl include_dir data_dir error_file
 #
 # Copyright The Mbed TLS Contributors
-# SPDX-License-Identifier: Apache-2.0
-#
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-# http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 
 use strict;
 use warnings;