crypto: morus - Add generic MORUS AEAD implementations

This patch adds the generic implementation of the MORUS family of AEAD
algorithms (MORUS-640 and MORUS-1280). The original authors of MORUS
are Hongjun Wu and Tao Huang.

At the time of writing, MORUS is one of the finalists in CAESAR, an
open competition intended to select a portfolio of alternatives to
the problematic AES-GCM:

https://competitions.cr.yp.to/caesar-submissions.html
https://competitions.cr.yp.to/round3/morusv2.pdf

Signed-off-by: Ondrej Mosnacek <omosnacek@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/morus_common.h

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The MORUS Authenticated-Encryption Algorithm
+ *   Common definitions
+ *
+ * Copyright (c) 2016-2018 Ondrej Mosnacek <omosnacek@gmail.com>
+ * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
+ *
+ * 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.
+ */
+
+#ifndef _CRYPTO_MORUS_COMMON_H
+#define _CRYPTO_MORUS_COMMON_H
+
+#define MORUS_BLOCK_WORDS 4
+#define MORUS_STATE_BLOCKS 5
+#define MORUS_NONCE_SIZE 16
+#define MORUS_MAX_AUTH_SIZE 16
+
+#endif /* _CRYPTO_MORUS_COMMON_H */