cifs: make CIFS depend on CRYPTO_MD4

Recently CIFS was changed to use the kernel crypto API for MD4 hashes,
but the Kconfig dependencies were not changed to reflect this.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reported-and-Tested-by: Suresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>