arm64: dts: qcom: sm8250: Add cpufreq hw node

arm64: dts: qcom: sm8250: Add cpufreq hw node

Add cpufreq HW device node to scale 4-Silver/3-Gold/1-Gold+ cores
on SM8250 SoCs.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Amit Kucheria <amitk@kernel.org>
Link: https://lore.kernel.org/r/20200915072423.18437-3-manivannan.sadhasivam@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>