When applying through a PNP, you generally sign something stating that you will settle in that province but there is no minimum time listed. You must intend to settle in that province at least when you apply as well as when you land as a PR. You might even have problems landing if you land in the wrong province unless you can convince them that you still intend to settle in your PNP province and will be going there.
However, after you have gotten your PR, you do of course have the freedom to travel to any province to visit as well as move there should you want to. There is a charter of rights and freedoms in Canada that states that a PR may live and work in any province.