Remove ATSU-related dead code from wxOSX

ATSU was deprecated for a long time and was finally removed from OS X
SDK in 10.11. wxOSX_USE_ATSU_TEXT was unconditionally disabled already,
so the code was never used and can be safely removed.

include/wx/osx/font.h

@@ -145,15 +145,6 @@ public:
 
     CTFontRef OSXGetCTFont() const;
 
-#if wxOSX_USE_ATSU_TEXT
-    // Returns an ATSUStyle not ATSUStyle*
-    void* MacGetATSUStyle() const ;
-    void* OSXGetATSUStyle() const { return MacGetATSUStyle() ; }
-
-    wxDEPRECATED( wxUint32 MacGetATSUFontID() const );
-    wxDEPRECATED( wxUint32 MacGetATSUAdditionalQDStyles() const );
-#endif
-
 #if wxOSX_USE_COCOA
     WX_NSFont OSXGetNSFont() const;
     static WX_NSFont OSXCreateNSFont(wxOSXSystemFont font, wxNativeFontInfo* info);