No you DO NOT need a new charger for the i7 CPU as you are NOT replacing the Power Supply or Battery
Your current 19V and 4.46A charger is fine for the i7 CPU as the i5 CPU uses the same voltage and Wattage
All you nee to do is replace your CPU and you are good to go. The CPU you will be needing is the Intel® Core i7 2630QM
Have a good day post back results when you are done