Core: remove deleted files from qbs file

These files have been removed with c3093cff.

Change-Id: I96b1c188bda8ff55a1cd4fba69c19f076be2efdb
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>

src/plugins/coreplugin/coreplugin.qbs

@@ -174,8 +174,6 @@ QtcPlugin {
         name: "ProgressManager_mac"
         condition: qbs.targetOS.contains("osx")
         files: [
-            "macfullscreen.h",
-            "macfullscreen.mm",
             "progressmanager/progressmanager_mac.mm",
         ]
     }