crypto: atmel - switch to SPDX license identifiers

Adopt the SPDX license identifiers to ease license compliance
management.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/atmel-tdes.c

@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Cryptographic API.
  *
@@ -6,10 +7,6 @@
  * Copyright (c) 2012 Eukréa Electromatique - ATMEL
  * Author: Nicolas Royer <nicolas@eukrea.com>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
- *
  * Some ideas are from omap-aes.c drivers.
  */