treewide: move copyrights and authors to AUTHORS

Also split "this is part of" line from copyright notices.

Change-Id: Ibc2446410bcb3104ead458b40a9ce7819c61a8eb
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41067
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>

util/msrtool/intel_atom.c

@@ -1,7 +1,5 @@
+/* This file is part of msrtool. */
 /*
- * This file is part of msrtool.
- *
- * Copyright (C) 2013 Olivier Langlois <olivier@olivierlanglois.net>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as