* STMicroelectronics 10/100/1000 Ethernet driver (GMAC)

Required properties:
- compatible: Should be "snps,dwmac-<ip_version>" "snps,dwmac"
	For backwards compatibility: "st,spear600-gmac" is also supported.
- reg: Address and length of the register set for the device
- interrupt-parent: Should be the phandle for the interrupt controller
  that services interrupts for this device
- interrupts: Should contain the STMMAC interrupts
- interrupt-names: Should contain the interrupt names "macirq"
  "eth_wake_irq" if this interrupt is supported in the "interrupts"
  property
- phy-mode: String, operation mode of the PHY interface.
  Supported values are: "mii", "rmii", "gmii", "rgmii".
- snps,phy-addr		phy address to connect to.
- snps,reset-gpio 	gpio number for phy reset.
- snps,reset-active-low boolean flag to indicate if phy reset is active low.
- snps,reset-delays-us  is triplet of delays
	The 1st cell is reset pre-delay in micro seconds.
	The 2nd cell is reset pulse in micro seconds.
	The 3rd cell is reset post-delay in micro seconds.
- snps,pbl		Programmable Burst Length
- snps,fixed-burst	Program the DMA to use the fixed burst mode
- snps,mixed-burst	Program the DMA to use the mixed burst mode

Optional properties:
- mac-address: 6 bytes, mac address

Examples:

	gmac0: ethernet@e0800000 {
		compatible = "st,spear600-gmac";
		reg = <0xe0800000 0x8000>;
		interrupt-parent = <&vic1>;
		interrupts = <24 23>;
		interrupt-names = "macirq", "eth_wake_irq";
		mac-address = [000000000000]; /* Filled in by U-Boot */
		phy-mode = "gmii";
	};
