arm64: dts: qcom: sm6350: Add SoC-specific compatible to cpufreq_hw

Add a SoC-specific compatbile to cpufreq_hw for compliancy with bindings.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Luca Weiss <luca.weiss@fairphone.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230308-topic-cpufreq_bindings-v1-7-3368473ec52d@linaro.org