util/scripts: add copyright notices

Change-Id: Ia40543e5585845e5e6c178a620052c6a25927a5c
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/17102
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/util/scripts/gerrit-rebase b/util/scripts/gerrit-rebase
index 002c499..8f59e7f 100755
--- a/util/scripts/gerrit-rebase
+++ b/util/scripts/gerrit-rebase
@@ -1,5 +1,18 @@
 #!/bin/bash
+
+# Copyright 2016 Google Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
 # $0 from-branch to-branch
+#
 # applies all commits that from-branch has over to-branch,
 # based on a common ancestor and gerrit meta-data
 from=$1