arm64: dts: qcom: sm8450: add spmi node

Add the spmi bus as found in the SM8450 SoC

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
[Konrad: 0x0 -> 0, move #cells down, make reg-names a vertical list]
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
[bjorn: Adjusted unit address]
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221229103212.984324-1-konrad.dybcio@linaro.org