whiskers: Add script to generate keypair for signing FW

Whiskers decided to leverage the key format of Hammer therefore this
script calls Hammer's one to generate a key pair and renames them to
key_whiskers*.

BUG=b:78254017
TEST=Run this script in the chroot and verify the generated key pair.
BRANCH=None

Change-Id: Iae7097a3b2da1b134fa1a986c669704bbbaca4e9
Reviewed-on: https://chromium-review.googlesource.com/1018591
Commit-Ready: Patrick Berny <pberny@chromium.org>
Tested-by: Patrick Berny <pberny@chromium.org>
Reviewed-by: Jason Clinton <jclinton@chromium.org>
Reviewed-by: Bob Moragues <moragues@chromium.org>

scripts/keygeneration/accessory/create_new_whiskers_keys.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+# Copyright 2018 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Load common constants and functions.
+. "$(dirname "$0")/common_leverage_hammer.sh"
+
+main() {
+  set -e
+
+  leverage_hammer_to_create_key "whiskers" "$@"
+}
+
+main "$@"