dt-bindings: PCI: layerscape-pci: Replace fsl,lx2160a-pcie with fsl,lx2160ar2-pcie

dt-bindings: PCI: layerscape-pci: Replace fsl,lx2160a-pcie with fsl,lx2160ar2-pcie

The fsl,lx2160a-pcie compatible is used for mobivel according to the
Documentation/devicetree/bindings/pci/layerscape-pcie-gen4.txt file.

Whereas the fsl,layerscape-pcie is used for DesignWare PCIe controller binding.

So change it to fsl,lx2160ar2-pcie and allow a fall back to fsl,ls2088a-pcie.

While at it, sort compatible string.

Fixes: 24cd7ecb3886 ("dt-bindings: PCI: layerscape-pci: Convert to YAML format")
Link: https://lore.kernel.org/linux-pci/20240826-2160r2-v1-1-106340d538d6@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>