rockchip: rk3399: split rockpro64 out of evb_rk3399

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>
diff --git a/configs/rockpro64-rk3399_defconfig b/configs/rockpro64-rk3399_defconfig
index 423148b..94279ed 100644
--- a/configs/rockpro64-rk3399_defconfig
+++ b/configs/rockpro64-rk3399_defconfig
@@ -2,6 +2,7 @@
 CONFIG_ARCH_ROCKCHIP=y
 CONFIG_SYS_TEXT_BASE=0x00200000
 CONFIG_ROCKCHIP_RK3399=y
+CONFIG_TARGET_ROCKPRO64_RK3399=y
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_DEBUG_UART_BASE=0xFF1A0000
 CONFIG_DEBUG_UART_CLOCK=24000000