powerpc: dts: p2020: Make usb@22000 node compatible for Linux kernel driver

Linux P2020 USB kernel driver uses compatible string fsl-usb2-dr-v1.6 and
needs more DT properties. Copy P2020 usb@22000 properties from upstream
Linux kernel.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>