OPP: refactor dev_pm_opp_of_register_em() and update related drivers

The Energy Model framework supports not only CPU devices. Drop the CPU
specific interface with cpumask and add struct device. Add also a return
value, user might use it. This new interface provides easy way to create
a simple Energy Model, which then might be used by e.g. thermal subsystem.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
index 20d1f85..b0f5388 100644
--- a/drivers/cpufreq/scpi-cpufreq.c
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -167,7 +167,7 @@ static int scpi_cpufreq_init(struct cpufreq_policy *policy)
 
 	policy->fast_switch_possible = false;
 
-	dev_pm_opp_of_register_em(policy->cpus);
+	dev_pm_opp_of_register_em(cpu_dev, policy->cpus);
 
 	return 0;