arm64: dts: qcom: sm8450: move SDHCI pin configuration to DTSI

The SDHCI pin configuration/mux nodes are actually common to all
upstreamed boards, so define them in SoC DTSI to reduce code
duplication.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221026200357.391635-2-krzysztof.kozlowski@linaro.org