dt-bindings: PCI: xilinx-nwl: Convert to YAML schemas of Xilinx NWL PCIe Root Port Bridge

Convert to YAML schemas for Xilinx NWL PCIe Root Port Bridge
dt binding.

Signed-off-by: Thippeswamy Havalige <thippeswamy.havalige@amd.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221111053709.1474323-2-thippeswamy.havalige@amd.com


Signed-off-by: Rob Herring <robh@kernel.org>