soc: rockchip: add header for ddr rate SIP interface

Add a header for the SIP interface defined to access the dcf controller
handling ddr rate changes on rk3399 (and most likely later socs).

This interface is shared between the clock driver as well as the
devfreq driver.

The SIP interface counterpart was merged from pull-request #684 [0]
into the upstream arm-trusted-firmware codebase.

[0] https://github.com/ARM-software/arm-trusted-firmware/pull/684

Signed-off-by: Lin Huang <[e-mail]>
Signed-off-by: Heiko Stuebner <[e-mail]>

include/soc/rockchip/rockchip_sip.h

···
+/*
+ * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
+ * Author: Lin Huang <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+#ifndef __SOC_ROCKCHIP_SIP_H
+#define __SOC_ROCKCHIP_SIP_H
+
+#define ROCKCHIP_SIP_DRAM_FREQ			0x82000008
+#define ROCKCHIP_SIP_CONFIG_DRAM_INIT		0x00
+#define ROCKCHIP_SIP_CONFIG_DRAM_SET_RATE	0x01
+#define ROCKCHIP_SIP_CONFIG_DRAM_ROUND_RATE	0x02
+#define ROCKCHIP_SIP_CONFIG_DRAM_SET_AT_SR	0x03
+#define ROCKCHIP_SIP_CONFIG_DRAM_GET_BW		0x04
+#define ROCKCHIP_SIP_CONFIG_DRAM_GET_RATE	0x05
+#define ROCKCHIP_SIP_CONFIG_DRAM_CLR_IRQ	0x06
+#define ROCKCHIP_SIP_CONFIG_DRAM_SET_PARAM	0x07
+
+#endif