I don't think there is (since it's a hardware feature) but I could be wrong. Besides, why would you want to disable it? At least you'll save some wear on the power button by using the Home button to wake it up. I've read that these buttons have a limited life, so I'll take any opportunity I can to conserve the power button's life.
Now if they would only give us the option to use the volume buttons to wake the phone...