arm64: tegra: Enable XUSB controller on Tegra210 Smaug

Enable the XUSB controller on Tegra210 Smaug. The Smaug has a USB Type-C
connector with one of the USB2.0 lanes and one of the USB3.0 lanes
populated.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>