IEEE 1588 Support

Note: In order to test the hardware platform, a 1588 timestamp capable timer is required at the h/w level. Prerequisite for 1588 testing:

     axi_ethernet_eth_buf: ethernet@40c00000 {
            axistream-connected = <&axi_dma_1>;
            axififo-connected = <&axi_fifo_0>;
            clock-frequency = <100000000>;
            clocks = <&clk_bus_0>;
            compatible = "xlnx,axi-ethernet-1.00.a";
            device_type = "network";
            interrupt-parent = <&microblaze_1_axi_intc>;
            interrupts = <4 2>;
            reg = <0x40c00000 0x40000>;
            xlnx,phy-type = <0x4>;
            xlnx,phyaddr = <0x1>;
            xlnx,rxcsum = <0x0>;
            xlnx,rxmem = <0x8000>;
            xlnx,txcsum = <0x0>;
            xlnx,txmem = <0x8000>;
            phy-handle = <&phy0>;
            mdio {
              #address-cells = <1>;
              #size-cells = <0>;
                  phy0: phy@7 {
                      compatible = "marvell,88e1111";
                     device_type = "ethernet-phy";
                     reg = <7>;
                };
            };
        };

MRMAC 1588 support is tested with Xilinx 1588 Timer-Syncer block details of which can be found here:

https://github.com/Xilinx/linux-xlnx/blob/master/Documentation/devicetree/bindings/ptp/ptp-xilinx.yaml

https://github.com/Xilinx/linux-xlnx/blob/master/drivers/ptp/ptp_xilinx.c