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/pcie.c b/arch/arm/mach-tegra/pcie.c
index 0e09137..d3ad515 100644
--- a/arch/arm/mach-tegra/pcie.c
+++ b/arch/arm/mach-tegra/pcie.c
@@ -723,9 +723,9 @@
 
 	tegra_pcie_xclk_clamp(false);
 
-	clk_enable(tegra_pcie.afi_clk);
-	clk_enable(tegra_pcie.pex_clk);
-	return clk_enable(tegra_pcie.pll_e);
+	clk_prepare_enable(tegra_pcie.afi_clk);
+	clk_prepare_enable(tegra_pcie.pex_clk);
+	return clk_prepare_enable(tegra_pcie.pll_e);
 }
 
 static int tegra_pcie_clocks_get(void)