arm64: dts: qcom: sm6115: Add CPU idle-states

Add CPU idle-state nodes and power-domains in Qualcomm sm6115 SoC dtsi.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230518080031.2509250-1-bhupesh.sharma@linaro.org