The term started in England with the old expression " Top of the morning to you". The term then was said when noble men would "tip" the "top" of there top hat in the sign of their well being. Hence they are tipping there top to signal they are in top shape or things are at the top of the order.
Snatch (2000)
Tommy: What's wrong with this one?
Turkish: sarcastically, as he pulls the caravan door off trying to open it Oh, nothing, Tommy. It's tip top. It's just I'm not sure about the colour.