Merge branch 'pci/portdrv'

- Squash portdrv_core.c and portdrv_pci.c into portdrv.c to make it easier
  to find things (Bjorn Helgaas)

- Allow AER service only for Root Ports & RCECs so portdrv can successfully
  bind to other devices that have AER but lack MSI (which they don't need
  for AER), which allows power management for those devices (Bjorn Helgaas)

* pci/portdrv:
  PCI/portdrv: Allow AER service only for Root Ports & RCECs
  PCI/portdrv: Unexport pcie_port_service_register(), pcie_port_service_unregister()
  PCI/portdrv: Move private things to portdrv.c
  PCI/portdrv: Squash into portdrv.c