amba: tegra-ahb: Fix warning w/o PM_SLEEP

Fix build warning w/o PM_SLEEP.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
diff --git a/drivers/amba/tegra-ahb.c b/drivers/amba/tegra-ahb.c
index 0b6f0b2..ce8fdad 100644
--- a/drivers/amba/tegra-ahb.c
+++ b/drivers/amba/tegra-ahb.c
@@ -156,6 +156,7 @@
 EXPORT_SYMBOL(tegra_ahb_enable_smmu);
 #endif
 
+#ifdef CONFIG_PM_SLEEP
 static int tegra_ahb_suspend(struct device *dev)
 {
 	int i;
@@ -175,6 +176,7 @@
 		gizmo_writel(ahb, ahb->ctx[i], tegra_ahb_gizmo[i]);
 	return 0;
 }
+#endif
 
 static UNIVERSAL_DEV_PM_OPS(tegra_ahb_pm,
 			    tegra_ahb_suspend,