rockchip: rk3399: Migrate to use common board file

Use common board file for board_init() and board_late_init(),
for Rockchip SoCs have very similar process.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
index 90916a3..4b21179 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -177,6 +177,7 @@
 	select DM_PMIC
 	select DM_REGULATOR_FIXED
 	select BOARD_LATE_INIT
+	imply ROCKCHIP_COMMON_BOARD
 	imply SPL_ROCKCHIP_COMMON_BOARD
 	imply TPL_SERIAL_SUPPORT
 	imply TPL_LIBCOMMON_SUPPORT
diff --git a/arch/arm/mach-rockchip/Makefile b/arch/arm/mach-rockchip/Makefile
index 210e80e..ca633af 100644
--- a/arch/arm/mach-rockchip/Makefile
+++ b/arch/arm/mach-rockchip/Makefile
@@ -22,7 +22,6 @@
 obj-y += boot_mode.o
 obj-$(CONFIG_ROCKCHIP_COMMON_BOARD) += board.o
 
-obj-$(CONFIG_ROCKCHIP_RK3399) += rk3399-board.o
 obj-$(CONFIG_ROCKCHIP_RV1108) += rv1108-board.o
 endif
 
diff --git a/arch/arm/mach-rockchip/rk3399-board.c b/arch/arm/mach-rockchip/rk3399-board.c
deleted file mode 100644
index 443c87c..0000000
--- a/arch/arm/mach-rockchip/rk3399-board.c
+++ /dev/null
@@ -1,13 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Copyright (c) 2017 Rockchip Electronics Co., Ltd
- */
-
-#include <common.h>
-#include <asm/arch-rockchip/boot_mode.h>
-
-int board_late_init(void)
-{
-	setup_boot_mode();
-	return 0;
-}