arm64: dts: qcom: sm6375: Add missing power-domain-named to CDSP

This was omitted when first introducing the node. Fix it.

Fixes: fe6fd26a ("arm64: dts: qcom: sm6375: Add ADSP&CDSP")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230109135647.339224-5-konrad.dybcio@linaro.org