arm64: dts: qcom: sc7180: add IPA information

Add IPA-related nodes and definitions to "sc7180.dtsi".

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20200518214939.9730-1-elder@linaro.org


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