add s2w
cpufreq: Store cpufreq policies in a list

Policies available in a cpufreq framework are now linked together. They are
accessible via cpufreq_policy_list defined at cpufreq core.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>