treewide: split off license text, remove extra copyright notices

Copyright notices are best stored in AUTHORS

Change-Id: Ib9025c58987ee2f7db600e038f5d3e4edc69aacc
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41203
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/lib/edid_fill_fb.c

@@ -1,6 +1,4 @@
 /*
- * Copyright 2013 Google Inc.
- *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation