arm64: dts: qcom: sm8550-qrd: add missing PCIE1 PHY AUX clock frequency

The SM8550 DTSI defines a fixed PCIE1 PHY AUX clock and expects boards
to define frequency.  Use the same as in MTP8550 to fix:

  sm8550-qrd.dtb: pcie-1-phy-aux-clk: 'clock-frequency' is a required property

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230416123730.300863-5-krzysztof.kozlowski@linaro.org