phy: Add Tegra XUSB pad controller support

Add a new driver for the XUSB pad controller found on NVIDIA Tegra SoCs.
This hardware block used to be exposed as a pin controller, but it turns
out that this isn't a good fit. The new driver and DT binding much more
accurately describe the hardware and are more flexible in supporting new
SoC generations.

Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 24596a9..d4f06e6 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -52,3 +52,5 @@
 obj-$(CONFIG_PHY_BRCMSTB_SATA)		+= phy-brcmstb-sata.o
 obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
 obj-$(CONFIG_PHY_CYGNUS_PCIE)		+= phy-bcm-cygnus-pcie.o
+
+obj-$(CONFIG_ARCH_TEGRA) += tegra/