crypto: s390 - clean up DES code a bit more

Commit 98971f84 ("crypto: s390 - cleanup
DES code") should have also removed crypto_des.h. That file is unused
and unneeded since that commit. So let's clean up that file too.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/s390/crypto/crypto_des.h

-/*
- * Cryptographic API.
- *
- * Function for checking keys for the DES and Tripple DES Encryption
- * algorithms.
- *
- * 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_DES_H__
-#define __CRYPTO_DES_H__
-
-extern int crypto_des_check_key(const u8*, unsigned int, u32*);
-
-#endif /*__CRYPTO_DES_H__*/