cpufreq: OMAP: Register an Energy Model

Try and register an Energy Model from omap-cpufreq.c to allow
interested subsystems like the task scheduler to use the provided
information.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/omap-cpufreq.c

@@ -133,8 +133,10 @@ static int omap_cpu_init(struct cpufreq_policy *policy)
 
 	/* FIXME: what's the actual transition time? */
 	result = cpufreq_generic_init(policy, freq_table, 300 * 1000);
-	if (!result)
+	if (!result) {
+		dev_pm_opp_of_register_em(policy->cpus);
 		return 0;
+	}
 
 	freq_table_free();
 fail: