arm64: dts: qcom: sa8155p-adp: Add support for uSD card

Add support for uSD card on SA8155p-ADP board using the SDHC2
interface.

Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220403144151.92572-3-bhupesh.sharma@linaro.org