rockchip: rk3368: Add core start-up code for RK3368

The RK3368 is an octa-core Cortex-A53 SoC from Rockchip.
This adds basic support to chain-load U-Boot from Rockchip's
miniloader.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-rockchip/rk3368/clk_rk3368.c b/arch/arm/mach-rockchip/rk3368/clk_rk3368.c
new file mode 100644
index 0000000..2f98165
--- /dev/null
+++ b/arch/arm/mach-rockchip/rk3368/clk_rk3368.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2017 Rockchip Electronics Co., Ltd
+ * Author: Andy Yan <andy.yan@rock-chips.org>
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <syscon.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/cru_rk3368.h>
+
+int rockchip_get_clk(struct udevice **devp)
+{
+	return uclass_get_device_by_driver(UCLASS_CLK,
+			DM_GET_DRIVER(rockchip_rk3368_cru), devp);
+}
+
+void *rockchip_get_cru(void)
+{
+	struct rk3368_clk_priv *priv;
+	struct udevice *dev;
+	int ret;
+
+	ret = rockchip_get_clk(&dev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	priv = dev_get_priv(dev);
+
+	return priv->cru;
+}