In the "Profile" section, there is a checkbox in the RRSP section that allows you to do this. If you check the checkbox for the following question, you will be able to carry forward your RRSPs.
I'd like to carry forward my RRSPs. (Not sure? Don't worry. What you choose here is not final. If you don't need to claim all of your RRSPs, TurboTax will let you know later.)