soc/tegra: pmc: Don't allocate struct tegra_powergate on stack

With a later commit an instance of the struct device will be added to
struct genpd and with that the size of the struct tegra_powergate will
be over 1024 bytes. That generates following warning:

drivers/soc/tegra/pmc.c:579:1: warning: the frame size of 1200 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Avoid such warnings by allocating the structure dynamically.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NThierry Reding <treding@nvidia.com>

drivers/soc/tegra/pmc.c

@@ -559,22 +559,28 @@ EXPORT_SYMBOL(tegra_powergate_remove_clamping);
 int tegra_powergate_sequence_power_up(unsigned int id, struct clk *clk,
 				      struct reset_control *rst)
 {
-	struct tegra_powergate pg;
+	struct tegra_powergate *pg;
 	int err;
 
 	if (!tegra_powergate_is_available(id))
 		return -EINVAL;
 
-	pg.id = id;
-	pg.clks = &clk;
-	pg.num_clks = 1;
-	pg.reset = rst;
-	pg.pmc = pmc;
+	pg = kzalloc(sizeof(*pg), GFP_KERNEL);
+	if (!pg)
+		return -ENOMEM;
 
-	err = tegra_powergate_power_up(&pg, false);
+	pg->id = id;
+	pg->clks = &clk;
+	pg->num_clks = 1;
+	pg->reset = rst;
+	pg->pmc = pmc;
+
+	err = tegra_powergate_power_up(pg, false);
 	if (err)
 		pr_err("failed to turn on partition %d: %d\n", id, err);
 
+	kfree(pg);
+
 	return err;
 }
 EXPORT_SYMBOL(tegra_powergate_sequence_power_up);