phy: tegra: xusb: Skip single function lane programming

Tegra186 USB2 pads and USB3 pads do not have hardware mux for changing
the pad function. For such "lanes", we can skip the lane mux register
programming.

Signed-off-by: JC Kuo <jckuo@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/tegra/xusb.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2015, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2016, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -313,6 +313,10 @@ static void tegra_xusb_lane_program(struct tegra_xusb_lane *lane)
 	const struct tegra_xusb_lane_soc *soc = lane->soc;
 	u32 value;
 
+	/* skip single function lanes */
+	if (soc->num_funcs < 2)
+		return;
+
 	/* choose function */
 	value = padctl_readl(padctl, soc->offset);
 	value &= ~(soc->mask << soc->shift);