cpufreq / CPPC: Support for CPPC v3

Use CPPC v3 entries to convert the abstract processor performance to
processor frequency in KHz.

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