drivers/rf: migrate license to ASF

Augusto Fraga Giachero has sumitted the ICLA and the license can be
replaced by the ASF License

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>

drivers/rf/dat-31r5-sp.c

@@ -1,17 +1,22 @@
 /****************************************************************************
  * drivers/rf/dat-31r5-sp.c
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
+ * SPDX-License-Identifier: Apache-2.0
- * 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
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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,
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
- * See the License for the specific language governing permissions and
+ * License for the specific language governing permissions and limitations
- * limitations under the License.
+ * under the License.
  *
  ****************************************************************************/