ARM64: rockchip: add support for rk3399 SoC based evb

RK3399 is a SoC from Rockchip with dual-core Cortex-A72
and quad-core Cortex-A53 CPU. It supports two USB3.0
type-C ports and two USB2.0 EHCI ports. Other interfaces
are very much like RK3288, the DRAM are 32bit width address
and support address from 0 to 4GB-128MB range.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/board/rockchip/evb_rk3399/evb-rk3399.c b/board/rockchip/evb_rk3399/evb-rk3399.c
new file mode 100644
index 0000000..dffacd0
--- /dev/null
+++ b/board/rockchip/evb_rk3399/evb-rk3399.c
@@ -0,0 +1,26 @@
+/*
+ * (C) Copyright 2016 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+#include <common.h>
+#include <asm/armv8/mmu.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int board_init(void)
+{
+	return 0;
+}
+
+int dram_init(void)
+{
+	gd->ram_size = 0x80000000;
+	return 0;
+}
+
+void dram_init_banksize(void)
+{
+	gd->bd->bi_dram[0].start = 0;
+	gd->bd->bi_dram[0].size = 0x80000000;
+}