arm64: dts: rockchip: use USB host by default on rk3399-rock-pi-4

arm64: dts: rockchip: use USB host by default on rk3399-rock-pi-4

Based on the board schematics at
https://dl.radxa.com/rockpi4/docs/hw/rockpi4/rockpi_4c_v12_sch_20200620.pdf
on page 19 there is an USB Type-A receptacle being used as an USB-OTG port.

But the Type-A connector is not valid for OTG operation, for this reason
there is a switch to select host or device role.
This is non-compliant and error prone because switching is manual.
So, use host mode as it corresponds for a Type-A receptacle.

Signed-off-by: Vicente Bergas <vicencb@gmail.com>
Link: https://lore.kernel.org/r/20201201154132.1286-4-vicencb@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>