Simplify SetFont() in wxOSX implementations

It doesn't need to take the colour and other parameters unused any more.

Closes https://github.com/wxWidgets/wxWidgets/pull/2103

include/wx/osx/cocoa/dataview.h

@@ -548,7 +548,7 @@ public:
     // Cocoa-specific helpers
     id GetItemAtRow(int row) const;
 
-    virtual void SetFont(const wxFont& font, const wxColour& foreground, long windowStyle, bool ignoreBlack = true);
+    virtual void SetFont(const wxFont& font);
 
 private:
     void InitOutlineView(long style);