Add Qt-Security tags to texture file reading code

According to QUIP-23

Pick-to: 6.8
Change-Id: I286f76e72a253b67b033a88d24bacdefb714e58f
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
(cherry picked from commit 5ef9b4efe1)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/gui/util/qastchandler.cpp

@@ -1,5 +1,6 @@
 // Copyright (C) 2019 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
+// Qt-Security score:critical reason:data-parser
 
 #include "qastchandler_p.h"
 #include "qtexturefiledata_p.h"

src/gui/util/qktxhandler.cpp

@@ -1,5 +1,6 @@
 // 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
+// Qt-Security score:critical reason:data-parser
 
 #include "qktxhandler_p.h"
 #include "qtexturefiledata_p.h"

src/gui/util/qpkmhandler.cpp

@@ -1,5 +1,6 @@
 // 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
+// Qt-Security score:critical reason:data-parser
 
 #include "qpkmhandler_p.h"
 #include "qtexturefiledata_p.h"

src/gui/util/qtexturefiledata.cpp

@@ -1,5 +1,6 @@
 // Copyright (C) 2018 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
+// Qt-Security score:critical reason:data-parser
 
 #include "QtGui/qimage.h"
 #include "qtexturefiledata_p.h"