dt-bindings: PCI: Fix 'unevaluatedProperties' warnings

With 'unevaluatedProperties' support implemented, there's several
warnings due to undocumented properties:

Documentation/devicetree/bindings/pci/mediatek,mt7621-pcie.example.dt.yaml: pcie@1e140000: pcie@0,0: Unevaluated properties are not allowed ('phy-names' was unexpected)
Documentation/devicetree/bindings/pci/mediatek,mt7621-pcie.example.dt.yaml: pcie@1e140000: pcie@1,0: Unevaluated properties are not allowed ('phy-names' was unexpected)
Documentation/devicetree/bindings/pci/mediatek,mt7621-pcie.example.dt.yaml: pcie@1e140000: pcie@2,0: Unevaluated properties are not allowed ('phy-names' was unexpected)
Documentation/devicetree/bindings/pci/mediatek-pcie-gen3.example.dt.yaml: pcie@11230000: Unevaluated properties are not allowed ('phy-names' was unexpected)
Documentation/devicetree/bindings/pci/microchip,pcie-host.example.dt.yaml: pcie@2030000000: Unevaluated properties are not allowed ('interrupt-controller' was unexpected)
Documentation/devicetree/bindings/pci/ti,am65-pci-ep.example.dt.yaml: pcie-ep@5500000: Unevaluated properties are not allowed ('num-ib-windows', 'num-ob-windows' were unexpected)
Documentation/devicetree/bindings/pci/ti,am65-pci-host.example.dt.yaml: pcie@5500000: Unevaluated properties are not allowed ('num-viewport', 'interrupts' were unexpected)
Documentation/devicetree/bindings/pci/ti,j721e-pci-host.example.dt.yaml: pcie@2900000: Unevaluated properties are not allowed ('dma-coherent' was unexpected)

Add the necessary property definitions or remove the properties from the
examples to fix these warnings.

Cc: Ryder Lee <ryder.lee@mediatek.com>
Cc: Jianjun Wang <jianjun.wang@mediatek.com>
Cc: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Daire McNamara <daire.mcnamara@microchip.com>
Cc: Abraham I <kishon@ti.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20211206194406.2469361-1-robh@kernel.org