dt-bindings: cpufreq: cpufreq-qcom-hw: Document Qcom EPSS compatible

The hardware block which carries out CPUFreq operations on SM8250 SoC is
called EPSS. Hence, document the compatible.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Amit Kucheria <amitk@kernel.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Author: Mani-Sadhasivam

Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-hw.txt

@@ -8,7 +8,7 @@ Properties:
 - compatible
 	Usage:		required
 	Value type:	<string>
-	Definition:	must be "qcom,cpufreq-hw".
+	Definition:	must be "qcom,cpufreq-hw" or "qcom,cpufreq-epss".
 
 - clocks
 	Usage:		required