arm64: zynqmp: Add phy description for usb3.0

usb3.0 requires serdes setting that's why also wire it up.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/cd856e5f87bc967373691d04e79de3d0022ef424.1623684253.git.michal.simek@xilinx.com