PM / devfreq: tegra: Set freq in rate callback

As per the documentation of the devfreq_dev_profile.target callback, set
the freq argument to the new frequency before returning.

This caused endless messages like this after recent changes in the core:

devfreq 6000c800.actmon: Couldn't update frequency transition information.
Signed-off-by: NTomeu Vizoso <tomeu.vizoso@collabora.com>
Reported-by: NTyler Baker <tyler.baker@linaro.org>
Tested-by: NThierry Reding <treding@nvidia.com>
Acked-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/tegra-devfreq.c

@@ -500,6 +500,8 @@ static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
 	clk_set_min_rate(tegra->emc_clock, rate);
 	clk_set_rate(tegra->emc_clock, 0);
 
+	*freq = rate;
+
 	return 0;
 }