Use SPDX identifier to Wintab attribution

We want to migrate away from non-spdx licenses in LicenseRef.
As there's no license equivalent in SPDX (yet), let's use a custom
license.

Pick-to: 6.7
Task-number: QTBUG-126403
Change-Id: Iaf705af167c63f76fa5c8d732272523a42c3b661
Reviewed-by: Lucie Gerard <lucie.gerard@qt.io>
(cherry picked from commit 5707bb2556108272185b62622354a24be23a7aaa)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/3rdparty/wintab/qt_attribution.json

@@ -3,11 +3,11 @@
     "Name": "Wintab API",
     "QDocModule": "qtgui",
     "QtUsage": "Used in the Qt platform plugin for Windows. Configure with -no-feature-tabletevent to avoid.",
+    "Files": ["pktdef.h", "wintab.h"],
 
     "Description": "Wintab is a de facto API for pointing devices on Windows.",
     "PackageComment": "Upstream http://www.pointing.com/Wintab.html no longer offers updates; treat as final",
     "License": "LCS-Telegraphics License",
-    "LicenseFile": "LICENSE.txt",
-    "LicenseId": "urn:dje:license:lcs-telegraphics",
+    "LicenseId": "LicenseRef-Lcs-Telegraphics",
     "Copyright": "Copyright 1991-1998 by LCS/Telegraphics."
 }