This is the only thing I found for you from droidxforums:
"My hard button lights still worked fine after rooting. I could wish I had your problem because I don't like them.
If you want to force them on all the time, you might try the app Adjbrightness. It has an option where you can force the button lights to stay on. (I use this app to force them off.) Maybe this will get you what you're looking for."
Hope it helps