I also have 3 AMD PCI drivers under System in Device Manager but it depends on your Motherboard and hardware installed.
You can find out what hardware it is for by clicking on the PCI Driver and then clicking on Details then click on the menu on HARDWARE ID.
Hardware ID will tell what hardware that PCI driver is for.
Here is my Device Manager showing the 3 AMD PCI drivers:
The one I am showing if for Hardware ID: 1022-1485 which is this: