dt-bindings: add rk3399 support for dw-mipi-rockchip

The dw-mipi-dsi of rk3399 is almost the same as rk3288, the rk3399 has
additional phy config clock.
Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1487577744-2855-2-git-send-email-zyw@rock-chips.com

Documentation/devicetree/bindings/display/rockchip/dw_mipi_dsi_rockchip.txt

@@ -5,10 +5,12 @@ Required properties:
 - #address-cells: Should be <1>.
 - #size-cells: Should be <0>.
 - compatible: "rockchip,rk3288-mipi-dsi", "snps,dw-mipi-dsi".
+	      "rockchip,rk3399-mipi-dsi", "snps,dw-mipi-dsi".
 - reg: Represent the physical address range of the controller.
 - interrupts: Represent the controller's interrupt to the CPU(s).
 - clocks, clock-names: Phandles to the controller's pll reference
-  clock(ref) and APB clock(pclk), as described in [1].
+  clock(ref) and APB clock(pclk). For RK3399, a phy config clock
+  (phy_cfg) is additional required. As described in [1].
 - rockchip,grf: this soc should set GRF regs to mux vopl/vopb.
 - ports: contain a port node with endpoint definitions as defined in [2].
   For vopb,set the reg = <0> and set the reg = <1> for vopl.