According to the MB specs there is no USB 2.0 port on the MB for the front panel. I believe the 8930 case only has USB 3.1 ports on the case. However have you thought about an adapter such as seen here?  Also another shown here. There are a number of those made by various manufacturers on the web for sale.
Hi, I recently upgraded my XPS 8930 with a new NZXT H510i Case. I was plugging in the USB 2.0 header but I couldn't find one on the board. Does the motherboard have a USB 2.0 header or is it just me. If there is a header can you show where it is. Thanks.
XPS 8930, NZXT H510i case swap