treewide: Remove "this file is part of" lines

Stefan thinks they don't add value.

Command used:
sed -i -e '/file is part of /d' $(git grep "file is part of " |egrep ":( */\*.*\*/\$|#|;#|-- | *\* )" | cut -d: -f1 |grep -v crossgcc |grep -v gcov | grep -v /elf.h |grep -v nvramtool)

The exceptions are for:
 - crossgcc (patch file)
 - gcov (imported from gcc)
 - elf.h (imported from GNU's libc)
 - nvramtool (more complicated header)

The removed lines are:
-       fmt.Fprintln(f, "/* This file is part of the coreboot project. */")
-# This file is part of a set of unofficial pre-commit hooks available
-/* This file is part of coreboot */
-# This file is part of msrtool.
-/* This file is part of msrtool. */
- * This file is part of ncurses, designed to be appended after curses.h.in
-/* This file is part of pgtblgen. */
- * This file is part of the coreboot project.
- /* This file is part of the coreboot project. */
-#  This file is part of the coreboot project.
-# This file is part of the coreboot project.
-## This file is part of the coreboot project.
--- This file is part of the coreboot project.
-/* This file is part of the coreboot project */
-/* This file is part of the coreboot project. */
-;## This file is part of the coreboot project.
-# This file is part of the coreboot project. It originated in the
- * This file is part of the coreinfo project.
-## This file is part of the coreinfo project.
- * This file is part of the depthcharge project.
-/* This file is part of the depthcharge project. */
-/* This file is part of the ectool project. */
- * This file is part of the GNU C Library.
- * This file is part of the libpayload project.
-## This file is part of the libpayload project.
-/* This file is part of the Linux kernel. */
-## This file is part of the superiotool project.
-/* This file is part of the superiotool project */
-/* This file is part of uio_usbdebug */

Change-Id: I82d872b3b337388c93d5f5bf704e9ee9e53ab3a9
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41194
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>