of_genpd_opp_to_performance_state() should return 0 for errors, but the
dummy routine isn't doing that. Fix it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>