AUTHORS, util/: Drop individual copyright notices

We have the git history which is a more reliable librarian.

Change-Id: Idbcc5ceeb33804204e56d62491cb58146f7c9f37
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41175
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: ron minnich <rminnich@gmail.com>

util/dtd_parser/dtd_parser.py

@@ -1,8 +1,6 @@
 #!/usr/bin/env python2
 # dtd_parser.py - DTD structure parser
 #
-# Copyright (C) 2012 The ChromiumOS Authors.  All rights reserved.
-#
 # 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