Add support for parameterized SipHash

The core SipHash supports either 8 or 16-byte output and a configurable
number of rounds.
The default behavior, as added to EVP, is to use 16-byte output and
2,4 rounds, which matches the behavior of most implementations.
There is an EVP_PKEY_CTRL that can control the output size.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2216)
diff --git a/util/mkdef.pl b/util/mkdef.pl
index c5884d3..99f5c9d 100755
--- a/util/mkdef.pl
+++ b/util/mkdef.pl
@@ -1,5 +1,5 @@
 #! /usr/bin/env perl
-# Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+# Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
 #
 # Licensed under the OpenSSL license (the "License").  You may not use
 # this file except in compliance with the License.  You can obtain a copy
@@ -82,6 +82,7 @@
 			 "MDC2", "WHIRLPOOL", "RSA", "DSA", "DH", "EC", "EC2M",
 			 "HMAC", "AES", "CAMELLIA", "SEED", "GOST",
                          "SCRYPT", "CHACHA", "POLY1305", "BLAKE2",
+			 "SIPHASH",
 			 # EC_NISTP_64_GCC_128
 			 "EC_NISTP_64_GCC_128",
 			 # Envelope "algorithms"