Merge branch 'pci/controller/rcar-gen4'

- Describe endpoint BAR 4 as being fixed size (Jerome Brunet)

- Document how to obtain R-Car V4H (r8a779g0) controller firmware
  (Yoshihiro Shimoda)

* pci/controller/rcar-gen4:
  PCI: rcar-gen4: Document how to obtain platform firmware
  PCI: rcar-gen4: set ep BAR4 fixed size