pci_scan_slot - scan a PCI slot on a bus for devices.
int __devinit pci_scan_slot (struct pci_bus * bus, int devfn);
bus PCI bus to scan devfn slot number to scan (must have zero function.)
Scan a PCI slot on the specified PCI bus for devices, adding discovered devices to the bus->devices list. New devices will have an empty dev->global_list head.