cpufreq: Set all cpus in policy->cpus for single cluster SoCs

With following patch, we need to set policy->cpus with mask of all possible cpus
and policy->related_cpus would be filled automatically by the core.

commit 4948b355e90080cd5ec1e91189f65a01e4186ef2
Author: Viresh Kumar <viresh.kumar@linaro.org>
Date:   Tue Jan 29 14:39:08 2013 +0000

cpufreq: Simplify cpufreq_add_dev()

Lets fix it for all single cluster SoCs.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>