relicense new source files under BSD

This project was started as a BSD licensed work, and it remained that
way even after the AOSP move, so make sure new files correctly reflect
that too.  Otherwise we end up with half the files using BSD and the
other half using Apache which is annoying.

Bug: None
Test: grepped for "apache" in all the files
Change-Id: I7cc7c890b42a1ded7552e1852246eaf86ca8428c
diff --git a/system.c b/system.c
index 11903a4..74e97c2 100644
--- a/system.c
+++ b/system.c
@@ -1,16 +1,6 @@
-/* Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+/* Copyright 2017 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.
  */
 
 #include "system.h"