phy: tegra: xusb: Add Tegra210 PLL power supplies

The Tegra210 SoC has four inputs that consume power in order to supply
the PLLs that drive the various USB, PCI and SATA pads.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>