arm64: dts: qcom: sm8450: Allow both GIC-ITS and internal MSI controller

The devicetree should specify both MSI implementations and the OS/driver
should choose the one based on the platform requirements. Currently, Linux
DWC driver will choose GIC-ITS over the internal MSI controller.

Fixes: a11bbf6adef4 ("arm64: dts: qcom: sm8450: Use GIC-ITS for PCIe0 and PCIe1")
Suggested-by: Rob Herring <robh@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230111123004.21048-2-manivannan.sadhasivam@linaro.org