Merge branch 'pci/enumeration'

Merge branch 'pci/enumeration'

- Clear LBMS bit after a manual link retrain so we don't try to retrain a
  link when there's no downstream device anymore (Maciej W. Rozycki)

- Revert to the original link speed after retraining fails instead of
  leaving it restricted to 2.5GT/s, so a future device has a chance to use
  higher speeds (Maciej W. Rozycki)

- Correct interpretation of pcie_retrain_link() return status and update it
  to return 0/errno instead of true/false (Maciej W.  Rozycki)

* pci/enumeration:
  PCI: Use an error code with PCIe failed link retraining
  PCI: Correct error reporting with PCIe failed link retraining
  PCI: Revert to the original speed after PCIe failed link retraining
  PCI: Clear the LBMS bit after a link retrain