Merge branch 'pci/enumeration'

  - Enable PCIe services for host controller drivers that use managed host
    bridge alloc (Jean-Philippe Brucker)

  - Add quirk to clear PCIe Retrain Link bit to work around Pericom bridge
    erratum (Stefan Mätje)

  - Add "external-facing" DT property to identify cases where we require
    IOMMU protection from untrusted devices (Jean-Philippe Brucker)

  - Support fixed bus numbers from bridge Enhanced Allocation capabilities
    (Subbaraya Sundeep)

* pci/enumeration:
  PCI: Assign bus numbers present in EA capability for bridges
  PCI: OF: Support "external-facing" property
  dt-bindings: Add "external-facing" PCIe port property
  PCI: Rework pcie_retrain_link() wait loop
  PCI: Work around Pericom PCIe-to-PCI bridge Retrain Link erratum
  PCI: Factor out pcie_retrain_link() function
  PCI: Init PCIe feature bits for managed host bridge alloc