Replace the current license disclaimer in files by
a SPDX-License-Identifier.
License files are organized under LICENSES directory.
Pick-to: 6.4
Task-number: QTBUG-67283
Change-Id: I3b3112f5a36673b90fff0010f973d020886cf08d
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
Lucie Gérard