soc/tegra: pmc: Drop the ->opp_to_performance_state() callback

Since commit 7c41cdcd ("OPP: Simplify the over-designed pstate <->
level dance"), there is no longer any need for genpd providers to assign
the ->opp_to_performance_state(), hence let's drop it.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/soc/tegra/pmc.c

@@ -1393,13 +1393,6 @@ tegra_pmc_core_pd_set_performance_state(struct generic_pm_domain *genpd,
 	return 0;
 }
 
-static unsigned int
-tegra_pmc_core_pd_opp_to_performance_state(struct generic_pm_domain *genpd,
-					   struct dev_pm_opp *opp)
-{
-	return dev_pm_opp_get_level(opp);
-}
-
 static int tegra_pmc_core_pd_add(struct tegra_pmc *pmc, struct device_node *np)
 {
 	struct generic_pm_domain *genpd;
@@ -1412,7 +1405,6 @@ static int tegra_pmc_core_pd_add(struct tegra_pmc *pmc, struct device_node *np)
 
 	genpd->name = "core";
 	genpd->set_performance_state = tegra_pmc_core_pd_set_performance_state;
-	genpd->opp_to_performance_state = tegra_pmc_core_pd_opp_to_performance_state;
 
 	err = devm_pm_opp_set_regulators(pmc->dev, rname);
 	if (err)