Merge branch 'pci/enumeration'

Merge branch 'pci/enumeration'

  - Work around IDT switch ACS Source Validation erratum (James
    Puthukattukaran)

  - Emit diagnostics for all cases of PCIe Link downtraining (Links
    operating slower than they're capable of) (Alexandru Gagniuc)

  - Skip VFs when configuring Max Payload Size (Myron Stowe)

  - Reduce Root Port Max Payload Size if necessary when hot-adding a device
    below it (Myron Stowe)

* pci/enumeration:
  PCI: Match Root Port's MPS to endpoint's MPSS as necessary
  PCI: Skip MPS logic for Virtual Functions (VFs)
  PCI: Check for PCIe Link downtraining
  PCI: Workaround IDT switch ACS Source Validation erratum