Revert back to 2.28.5

git revert v2.28.5..v2.28.6
git rebase to combine the resulting revert commits

This reverts commit 3a91dad9dceb484eea8b41f8941facafc4520021.
diff --git a/include/mbedtls/rsa_internal.h b/include/mbedtls/rsa_internal.h
index 286cff2..017018b 100644
--- a/include/mbedtls/rsa_internal.h
+++ b/include/mbedtls/rsa_internal.h
@@ -36,7 +36,19 @@
  */
 /*
  *  Copyright The Mbed TLS Contributors
- *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+ *  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.
  *
  */