cpufreq: use memcpy() to copy policy

cpufreq_get_policy() is useful if the pointer to policy isn't available
in advance. But if it is available, then there is no need to call
cpufreq_get_policy(). Directly use memcpy() to copy the policy.

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

Oiginal commit: https://github.com/powervm/ibmvscsis/commit/8fa5b631f32238a16ae3db0db5b354f7b9eb20cb