arm64: dts: qcom: sm8250: Add SDHCI2 sleep mode pinctrl

Add required pins for SDHCI2, so that the interface can work reliably.
This commit adds sleep_state setup to the SoC DTSI, as it is common for
all boards.

Signed-off-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Link: https://lore.kernel.org/r/20210616002321.74155-2-konrad.dybcio@somainline.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>