crypto: morus - Cleanup license mess

crypto: morus - Cleanup license mess

Precise and non-ambiguous license information is important. The recently
added morus header files have a SPDX license identifier, which is nice, but
at the same time they have a contradictionary license boiler plate text.

  SPDX-License-Identifier: GPL-2.0

versus

  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option)
  * any later version

Oh well.

As the other morus related files are licensed under the GPL v2 or later,
it's assumed that the boiler plate code is correct, but the SPDX license
identifier is wrong.

Fix the SPDX identifier and remove the boiler plate as it is redundant.

Fixes: 56e8e57fc3a7 ("crypto: morus - Add common SIMD glue code for MORUS")
Fixes: 396be41f16fd ("crypto: morus - Add generic MORUS AEAD implementations")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ondrej Mosnacek <omosnacek@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Acked-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>