* Rockchip DFI device

Required properties:
- compatible: Should be one of the following.
  - "rockchip,px30-dfi" - for PX30 SoCs.
  - "rockchip,rk1808-dfi" - for RK1808 SoCs.
  - "rockchip,rk3128-dfi" - for RK3128 SoCs.
  - "rockchip,rk3288-dfi" - for RK3288 SoCs.
  - "rockchip,rk3328-dfi" - for RK3328 SoCs.
  - "rockchip,rk3368-dfi" - for RK3368 SoCs.
  - "rockchip,rk3399-dfi" - for RK3399 SoCs.
  - "rockchip,rk3528-dfi" - for RK3528 SoCs.
  - "rockchip,rk3568-dfi" - for RK3568 SoCs.
  - "rockchip,rv1126-dfi" - for RV1126 SoCs.

Required properties for RK3368:
- rockchip,grf: phandle to the syscon managing the "general register files"

Required properties for RK3399:
- reg: physical base address of each DFI and length of memory mapped region
- rockchip,pmu: phandle to the syscon managing the "pmu general register files"
- clocks: phandles for clock specified in "clock-names" property
- clock-names : the name of clock used by the DFI, must be "pclk_ddr_mon";

Example:
	dfi: dfi@ff630000 {
		compatible = "rockchip,rk3399-dfi";
		reg = <0x00 0xff630000 0x00 0x4000>;
		rockchip,pmu = <&pmugrf>;
		clocks = <&cru PCLK_DDR_MON>;
		clock-names = "pclk_ddr_mon";
	};