ARM: brcmstb: add misc. DT bindings for brcmstb

ARM Broadcom STB platforms Device Tree Bindings

-----------------------------------------------

Boards with Broadcom Brahma15 ARM-based BCMxxxx (generally BCM7xxx variants)

SoC shall have the following DT organization:

Required root node properties:

    - compatible: "brcm,bcm<chip_id>", "brcm,brcmstb"

example:

/ {

    #address-cells = <2>;

    #size-cells = <2>;

    model = "Broadcom STB (bcm7445)";

    compatible = "brcm,bcm7445", "brcm,brcmstb";

Further, syscon nodes that map platform-specific registers used for general

system control is required:

    - compatible: "brcm,bcm<chip_id>-sun-top-ctrl", "syscon"

    - compatible: "brcm,bcm<chip_id>-hif-cpubiuctrl", "syscon"

    - compatible: "brcm,bcm<chip_id>-hif-continuation", "syscon"

example:

    rdb {

        #address-cells = <1>;

        #size-cells = <1>;

        compatible = "simple-bus";

        ranges = <0 0x00 0xf0000000 0x1000000>;

        sun_top_ctrl: syscon@404000 {

            compatible = "brcm,bcm7445-sun-top-ctrl", "syscon";

            reg = <0x404000 0x51c>;

        };

        hif_cpubiuctrl: syscon@3e2400 {

            compatible = "brcm,bcm7445-hif-cpubiuctrl", "syscon";

            reg = <0x3e2400 0x5b4>;

        };

        hif_continuation: syscon@452000 {

            compatible = "brcm,bcm7445-hif-continuation", "syscon";

            reg = <0x452000 0x100>;

        };

    };

Lastly, nodes that allow for support of SMP initialization and reboot are

required:

smpboot

-------

Required properties:

    - compatible

        The string "brcm,brcmstb-smpboot".

    - syscon-cpu

        A phandle / integer array property which lets the BSP know the location

        of certain CPU power-on registers.

        The layout of the property is as follows:

            o a phandle to the "hif_cpubiuctrl" syscon node

            o offset to the base CPU power zone register

            o offset to the base CPU reset register

    - syscon-cont

        A phandle pointing to the syscon node which describes the CPU boot

        continuation registers.

            o a phandle to the "hif_continuation" syscon node

example:

    smpboot {

        compatible = "brcm,brcmstb-smpboot";

        syscon-cpu = <&hif_cpubiuctrl 0x88 0x178>;

        syscon-cont = <&hif_continuation>;

    };

reboot

-------

Required properties

    - compatible

        The string property "brcm,brcmstb-reboot".

    - syscon

        A phandle / integer array that points to the syscon node which describes

        the general system reset registers.

            o a phandle to "sun_top_ctrl"

            o offset to the "reset source enable" register

            o offset to the "software master reset" register

example:

    reboot {

        compatible = "brcm,brcmstb-reboot";

        syscon = <&sun_top_ctrl 0x304 0x308>;

    };