scripts: Add copyright statements to files without one

Where there isn't a copyright statement, add one to make it explicit.
Also drop editor config lines where they were present and add license
identifiers as MIT if there isn't one.

(From OE-Core rev: deb3ccec53e0bd63bc4235cf2b0d3fc781687361)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/bitbake-whatchanged

@@ -1,7 +1,5 @@
 #!/usr/bin/env python3
-# ex:ts=4:sw=4:sts=4:et
-# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
-
+#
 # Copyright (c) 2013 Wind River Systems, Inc.
 #
 # SPDX-License-Identifier: GPL-2.0-only