LICENSE: update with latest text

Change-Id: Ieebea089095d9073b3a94932791099f614ce120c
diff --git a/ivfenc.c b/ivfenc.c
index 4d96d46..57c04dd 100644
--- a/ivfenc.c
+++ b/ivfenc.c
@@ -1,10 +1,11 @@
 /*
  *  Copyright (c) 2010 The VP8 project authors. All Rights Reserved.
  *
- *  Use of this source code is governed by a BSD-style license and patent
- *  grant that can be found in the LICENSE file in the root of the source
- *  tree. All contributing project authors may be found in the AUTHORS
- *  file in the root of the source tree.
+ *  Use of this source code is governed by a BSD-style license 
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may 
+ *  be found in the AUTHORS file in the root of the source tree.
  */