CMake: Remove static defaultValue method from CMakeKitInformation

There is no need to expose this.

Change-Id: I164f1e787b742d330282125320b54a5b2ecb6134
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/plugins/cmakeprojectmanager/cmakekitinformation.h

@@ -43,7 +43,6 @@ public:
 
     static CMakeTool *cmakeTool(const ProjectExplorer::Kit *k);
     static void setCMakeTool(ProjectExplorer::Kit *k, const Core::Id id);
-    static Core::Id defaultValue();
 
     // KitInformation interface
     QVariant defaultValue(const ProjectExplorer::Kit *k) const override;