riscv: dts: starfive: jh7110-milkv-mars: enable usb0 host function

Milk-V Mars board routes one of four USB-A ports to USB0 on the SoC
rather than to the VL805 USB 3.0 <-> PCIe chip.
Set JH7110 on-chip USB host mode and vbus pin assignment accordingly.

Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: E Shattow <e@freeshell.de>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>