net: axienet: add support for standard phy-mode binding

Keep supporting proprietary "xlnx,phy-type" attribute and add support for
MII connectivity to the PHY.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Alvaro Gamez Machado <alvaro.gamez@hazent.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/xilinx_axienet.txt

@@ -0,0 +1,55 @@
+XILINX AXI ETHERNET Device Tree Bindings
+--------------------------------------------------------
+
+Also called  AXI 1G/2.5G Ethernet Subsystem, the xilinx axi ethernet IP core
+provides connectivity to an external ethernet PHY supporting different
+interfaces: MII, GMII, RGMII, SGMII, 1000BaseX. It also includes two
+segments of memory for buffering TX and RX, as well as the capability of
+offloading TX/RX checksum calculation off the processor.
+
+Management configuration is done through the AXI interface, while payload is
+sent and received through means of an AXI DMA controller. This driver
+includes the DMA driver code, so this driver is incompatible with AXI DMA
+driver.
+
+For more details about mdio please refer phy.txt file in the same directory.
+
+Required properties:
+- compatible	: Must be one of "xlnx,axi-ethernet-1.00.a",
+		  "xlnx,axi-ethernet-1.01.a", "xlnx,axi-ethernet-2.01.a"
+- reg		: Address and length of the IO space.
+- interrupts	: Should be a list of two interrupt, TX and RX.
+- phy-handle	: Should point to the external phy device.
+		  See ethernet.txt file in the same directory.
+- xlnx,rxmem	: Set to allocated memory buffer for Rx/Tx in the hardware
+
+Optional properties:
+- phy-mode	: See ethernet.txt
+- xlnx,phy-type	: Deprecated, do not use, but still accepted in preference
+		  to phy-mode.
+- xlnx,txcsum	: 0 or empty for disabling TX checksum offload,
+		  1 to enable partial TX checksum offload,
+		  2 to enable full TX checksum offload
+- xlnx,rxcsum	: Same values as xlnx,txcsum but for RX checksum offload
+
+Example:
+	axi_ethernet_eth: ethernet@40c00000 {
+		compatible = "xlnx,axi-ethernet-1.00.a";
+		device_type = "network";
+		interrupt-parent = <&microblaze_0_axi_intc>;
+		interrupts = <2 0>;
+		phy-mode = "mii";
+		reg = <0x40c00000 0x40000>;
+		xlnx,rxcsum = <0x2>;
+		xlnx,rxmem = <0x800>;
+		xlnx,txcsum = <0x2>;
+		phy-handle = <&phy0>;
+		axi_ethernetlite_0_mdio: mdio {
+			#address-cells = <1>;
+			#size-cells = <0>;
+			phy0: phy@0 {
+				device_type = "ethernet-phy";
+				reg = <1>;
+			};
+		};
+	};