rockchip: rk3328: add soc basic support

RK3328 is a SoC from Rockchip with quad-core Cortex-A53 CPU.
It supports 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-16MB range.

Signed-off-by: William Zhang <william.zhang@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Add empty arch/arm/mach-rockchip/rk3328/Kconfig to avoid build error:
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-rockchip/rk3328/syscon_rk3328.c b/arch/arm/mach-rockchip/rk3328/syscon_rk3328.c
new file mode 100644
index 0000000..a1a368f
--- /dev/null
+++ b/arch/arm/mach-rockchip/rk3328/syscon_rk3328.c
@@ -0,0 +1,20 @@
+/*
+ * (C) Copyright 2016 Rockchip Electronics Co., Ltd
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/arch/clock.h>
+#include <dm.h>
+#include <syscon.h>
+
+static const struct udevice_id rk3328_syscon_ids[] = {
+	{ .compatible = "rockchip,rk3328-grf", .data = ROCKCHIP_SYSCON_GRF },
+};
+
+U_BOOT_DRIVER(syscon_rk3328) = {
+	.name = "rk3328_syscon",
+	.id = UCLASS_SYSCON,
+	.of_match = rk3328_syscon_ids,
+};