It is a classic quotation (not that ancient)! "Hey nonny nonny " is used as a catchy phrase to rythm a tone in a poem for example The word "nonny" : to nonny signifies to play with , to trifle nonny could also mean silly fellow .

In English and Scottish Balladry, "hey, nonny, nonny" is called a "nonsense phrase." It isn't supposed to mean anything. Citation from http://www.shaksper.net/archives/1994/0251.html