* 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: See ethernet.txt file in the same directory.
- 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
- snps,force_thresh_dma_mode	Force DMA to use the threshold mode for
				both tx and rx
- snps,force_sf_dma_mode	Force DMA to use the Store and Forward
				mode for both tx and rx. This flag is
				ignored if force_thresh_dma_mode is set.

Optional properties:
- resets: Should contain a phandle to the STMMAC reset signal, if any
- reset-names: Should contain the reset signal name "stmmaceth", if a
	reset phandle is given
- max-frame-size: See ethernet.txt file in the same directory
- clocks: If present, the first clock should be the GMAC main clock,
  further clocks may be specified in derived bindings.
- clocks-names: One name for each entry in the clocks property, the
  first one should be "stmmaceth".

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 */
		max-frame-size = <3800>;
		phy-mode = "gmii";
		clocks = <&clock>;
		clock-names = "stmmaceth">;
	};
