ARM: tegra30: clk: Fix output_rate overflow

Change the type of variable from "unsigned long" to "u64".
This avoids the overflow while clock rate calculating.

Signed-off-by: Mark Zhang <markz@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/mach-tegra/tegra30_clocks.c b/arch/arm/mach-tegra/tegra30_clocks.c
index 5cd502c..e9de5df 100644
--- a/arch/arm/mach-tegra/tegra30_clocks.c
+++ b/arch/arm/mach-tegra/tegra30_clocks.c
@@ -1199,7 +1199,7 @@
 {
 	struct clk_tegra *c = to_clk_tegra(hw);
 	unsigned long input_rate = *prate;
-	unsigned long output_rate = *prate;
+	u64 output_rate = *prate;
 	const struct clk_pll_freq_table *sel;
 	struct clk_pll_freq_table cfg;
 	int mul;