arm64: dts: rockchip: add USB2 to rk3588-rock5b

arm64: dts: rockchip: add USB2 to rk3588-rock5b

Enable USB2 (EHCI and OCHI mode) support for the Radxa ROCK 5 Model B.
This adds USB support on the M.2 Key E, both USB2 ports and USB2 mode
for the upper USB3 port (the one further away from the PCB).

The lower USB3 (closer to the PCB) and the USB-C ports use the RK3588
USB TypeC host controller, which is not yet supported upstream.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20230712165106.65603-4-sebastian.reichel@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>