J721e has 2 USB super-speed controllers add them.

The USB2 PHY doesn't need any configuration.
USB3 PHY needs to be implemented using the Cadence
Sierra PHY. This support will be added later.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Tero Kristo <t-kristo@ti.com>