It's not a typo, it's been explained a few different times. It is 'cutesy baby speak', like how adults talk to babies or animals. It is a word used around where the developers are from, I don't see why they should change it.
I could understand it being kind of a "double typo" - maybe it is not supposed to be "little" but indeed "liddle" ("liddle" is the official kids speek for little as it is a softer sound and easier to pronounce)Makes sense to me...I assumed as much seeing as a typo where you type "kk" instead of "tt" or even "dd" as suggested above would be almost impossible to accomplish. Those keys don't even use the same hand, much less the same fingers...