cpufreq: arm_scmi: Discover the power scale in performance protocol

Add mechanism to discover the power scale present in the performance
protocol for all domains. Provide this information to Energy Model,
which then can be checked in other frameworks, e.g. thermal.
Suggested-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/scmi-cpufreq.c

@@ -125,6 +125,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
 	struct scmi_data *priv;
 	struct cpufreq_frequency_table *freq_table;
 	struct em_data_callback em_cb = EM_DATA_CB(scmi_get_cpu_power);
+	bool power_scale_mw;
 
 	cpu_dev = get_cpu_device(policy->cpu);
 	if (!cpu_dev) {
@@ -188,8 +189,9 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
 	policy->fast_switch_possible =
 		handle->perf_ops->fast_switch_possible(handle, cpu_dev);
 
+	power_scale_mw = handle->perf_ops->power_scale_mw_get(handle);
 	em_dev_register_perf_domain(cpu_dev, nr_opp, &em_cb, policy->cpus,
-				    false);
+				    power_scale_mw);
 
 	return 0;