PCCard is used by PowerBook G3 Wallstreet in Open Firmware 2.0.1.
CardBus is probed in New World Macs starting from at least Open Firmware 4.1.9f1 sometime after Open Firmware 3.1.1.
- Create PCIBase from common stuff in PCIDevice.
- Add PCIBridgeBase. These have a primary bus number, secondary bus number, and subordinate bus number which are used to determine if PCI type 1 config cycle should be passed.
- Change PCIBridge to use PCIBridgeBase instead of PCIDevice.
- Add PCICardBusBridge which uses PCIBridgeBase.
