That is a feature of the motherboard as far as i can tell there is no way to do it.
GIGABYTE On/Off Charge
GIGABYTE 7 series motherboards feature ON/OFF Charge, a unique GIGAYTE technology which allows you not only to charge your iPhone, iPad or iPod Touch, but also allows you to Quick Charge it. As an added bonus, it can even be charged when your PC is turned off, so even if you forget to plug it into your charger after you've synced up your music, it will be fully charged when you need it.