PCI: portdrv: remove redundant pcie type calculation

PCIe port type is already stored in 'pcie_type' field of struct
pci_dev. So we don't need to get it from pci configuration space.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>