Hisilicon LPDDRC PMU comtrollers

Required properties:
  - compatible : should be "hisilicon,lpddrc-pmu".
  - reg : should contain at least address and length of the LPDDRC PMU
    register set for the device.
  - interrupts : one LPDDRC interrupt should be described here.

Example
    lpddrc0@A5800000 {
        compatible = "hisilicon,lpddrc-pmu";
        hisilicon,ch-id = <0>;
        hisilicon,scl-id = <1>;
        reg = <0x0 0xA5800000 0x0 0x10000>;
        interrupts = <0x0 32 0x4>;
    };
