rockpro64 needs to setup I/O domains in order for USB to work in u-boot.
Since we currently don't have a driver to do that, split it into its own
board file and initialize I/O domains here.
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
