change license to file that mostly based on TF-M implementation

from Apache-2.0 to BSD-3-Clause

components/TARGET_PSA/services/attestation/COMPONENT_PSA_SRV_IMPL/attest_crypto.c

@@ -1,20 +1,12 @@
 /*
-* Copyright (c) 2018-2019 ARM Limited. All rights reserved.
-*
-* 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.
-*/
+ * attest_crypto.c
+ *
+ * Copyright (c) 2018-2019, Laurence Lundblade. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * See BSD-3-Clause license in README.md
+ */
 
 #include "t_cose_crypto.h"
 #include "tfm_plat_defs.h"