None is the easy answer.
The yoke (and Throttle) alone don’t use anywhere near the USB 2 limit for current let alone that for USB3.
The power socket is for the USB hub on the yoke body can be used to add other peripherals, then you would need to power the hub (depending). i think this was intended for rudders, radio panels etc. Far better to use a decent powered USB3 Hub instead 
So, just plug it into USB and it will be fine. If you have any problems that ppear to be power related either plug the yoke into a powered hub or try another socket on your pc.
If memory serves, the PSU is 5V DC, 2 amp would more than plenty (it is USB 1.1 I think).