Correct license

According to QUIP-18 [1], all build system files
should be BSD-3-Clause.
The files in this patch are part of the build system.

[1]: https://contribute.qt-project.org/quips/18

Task-number: QTBUG-121787
Change-Id: I9a79fb04971b117515ed16b3978435ad8ef0e31f
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
(cherry picked from commit 08b8f9dd2f3e792a6fb43b7e065a7123dff74313)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

mkspecs/features/data/dumpvcvars.bat

@@ -1,5 +1,5 @@
 :: Copyright (C) 2018 The Qt Company Ltd.
-:: SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+:: SPDX-License-Identifier: BSD-3-Clause
 
 @echo off
 

mkspecs/features/data/mac/objc_namespace.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 # Copyright (C) 2017 The Qt Company Ltd.
-# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+# SPDX-License-Identifier: BSD-3-Clause
 
 script_argument_prefix="-Wobjc_namespace,--"
 

mkspecs/features/uikit/device_destinations.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 # Copyright (C) 2016 The Qt Company Ltd.
-# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+# SPDX-License-Identifier: BSD-3-Clause
 
 DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 scheme=$1

mkspecs/features/uikit/devices.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 # Copyright (C) 2017 The Qt Company Ltd.
-# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+# SPDX-License-Identifier: BSD-3-Clause
 
 from __future__ import print_function