dt-bindings: PCI: qcom-ep: Add support for SM8450 SoC

Add devicetree bindings support for SM8450 SoC. Only the clocks are
different on this platform, rest is same as SDX55.

Link: https://lore.kernel.org/r/20220914075350.7992-12-manivannan.sadhasivam@linaro.org


Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>