ARM: tegra: add clk_prepare/clk_unprepare

Use clk_prepare/clk_unprepare as required by the generic clk framework.

Tested on Ventana and Cardhu.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/mach-tegra/timer.c b/arch/arm/mach-tegra/timer.c
index 315672c..57b5bdc 100644
--- a/arch/arm/mach-tegra/timer.c
+++ b/arch/arm/mach-tegra/timer.c
@@ -189,7 +189,7 @@
 			" Assuming 12Mhz input clock.\n");
 		rate = 12000000;
 	} else {
-		clk_enable(clk);
+		clk_prepare_enable(clk);
 		rate = clk_get_rate(clk);
 	}
 
@@ -201,7 +201,7 @@
 	if (IS_ERR(clk))
 		pr_warn("Unable to get rtc-tegra clock\n");
 	else
-		clk_enable(clk);
+		clk_prepare_enable(clk);
 
 	switch (rate) {
 	case 12000000: