Phytium KCS (Keyboard Controller Style) IPMI interface

The Phytium E-series SOC (E2000) can be used in BMC which
have the KCS interface to perform in-band IPMI communication
with their host.

Required properties:
- compatible : should be one of
               "phytium,e2000-kcs-bmc"
- reg        : physical address and size of the registers
- interrupts : interrupt generated by the controller
- kcs_chan   : The LPC channel number in the controller
- kcs_addr   : The host CPU IO map address

Example:

    kcs0: kcs@24 {
        compatible = "phytium,e2000-kcs-bmc";
        reg = <0x24 0x1>, <0x30 0x1>, <0x3c 0x1>;
        interrupts = <GIC_SPI 88 IRQ_TYPE_LEVEL_HIGH>;
        kcs_chan = <1>;
        kcs_addr = <0xca0>;
    };
