Merge branch 'pci/dt-bindings'

- Add Qualcomm QCS615 to SM8150 DT binding (Ziyue Zhang)

- Add Qualcomm QCS8300 to SA8775p DT binding (Ziyue Zhang)

- Add '6' (64 GT/s, aka Gen6) as a legal value for the DT endpoint
  'max-link-speed' property (Hans Zhang)

- Drop TBU and ref clocks from Qualcomm SM8150 and SC8180x DT bindings
  (Konrad Dybcio)

- Convert amazon,al-alpine-v[23]-pcie, apm,xgene-pcie, axis,artpec6-pcie,
  marvell,armada-3700-pcie, st,spear1340-pcie to DT schema format (Rob
  Herring)

- Document 'link_down' reset in Qualcomm SA8775P DT binding (Ziyue Zhang)

* pci/dt-bindings:
  dt-bindings: PCI: qcom,pcie-sa8775p: Document 'link_down' reset
  dt-bindings: PCI: Remove 83xx-512x-pci.txt
  dt-bindings: PCI: Convert amazon,al-alpine-v[23]-pcie to DT schema
  dt-bindings: PCI: Convert marvell,armada-3700-pcie to DT schema
  dt-bindings: PCI: Convert apm,xgene-pcie to DT schema
  dt-bindings: PCI: Convert axis,artpec6-pcie to DT schema
  dt-bindings: PCI: Convert st,spear1340-pcie to DT schema
  dt-bindings: PCI: qcom,pcie-sm8150: Drop unrelated clocks from PCIe hosts
  dt-bindings: PCI: qcom,pcie-sc8180x: Drop unrelated clocks from PCIe hosts
  dt-bindings: PCI: pci-ep: Extend max-link-speed to PCIe Gen5/Gen6
  dt-bindings: PCI: qcom,pcie-sa8775p: Document QCS8300
  dt-bindings: PCI: qcom,pcie-sm8150: Document QCS615