net: nixge: Update device-tree bindings with v3.00

* NI XGE Ethernet controller

Required properties:

- compatible: Should be "ni,xge-enet-2.00"

- reg: Address and length of the register set for the device

- compatible: Should be "ni,xge-enet-3.00", but can be "ni,xge-enet-2.00" for

              older device trees with DMA engines co-located in the address map,

              with the one reg entry to describe the whole device.

- reg: Address and length of the register set for the device. It contains the

       information of registers in the same order as described by reg-names.

- reg-names: Should contain the reg names

	"dma":  DMA engine control and status region

        "ctrl": MDIO and PHY control and status region

- interrupts: Should contain tx and rx interrupt

- interrupt-names: Should be "rx" and "tx"

- phy-mode: See ethernet.txt file in the same directory.

Examples (10G generic PHY):

	nixge0: ethernet@40000000 {

		compatible = "ni,xge-enet-2.00";

		reg = <0x40000000 0x6000>;

		compatible = "ni,xge-enet-3.00";

		reg = <0x40000000 0x4000

		       0x41002000 0x2000>;

		reg-names = "dma", "ctrl";

		nvmem-cells = <&eth1_addr>;

		nvmem-cell-names = "address";