dt-bindings: PCI: qcom: Add sm8350 to bindings

Add bindings for two PCIe hosts on SM8350 platform. The only difference
between them is in the aggre0 clock, which warrants the oneOf clause for
the clocks properties.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>