dt-bindings: net: xilinx: document xilinx emaclite driver binding

Add basic description for the xilinx emaclite driver DT bindings.
Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/xlnx,emaclite.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/xlnx,emaclite.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xilinx Emaclite Ethernet controller
+
+maintainers:
+  - Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
+  - Harini Katakam <harini.katakam@amd.com>
+
+allOf:
+  - $ref: ethernet-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - xlnx,opb-ethernetlite-1.01.a
+      - xlnx,opb-ethernetlite-1.01.b
+      - xlnx,xps-ethernetlite-1.00.a
+      - xlnx,xps-ethernetlite-2.00.a
+      - xlnx,xps-ethernetlite-2.01.a
+      - xlnx,xps-ethernetlite-3.00.a
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  phy-handle: true
+
+  local-mac-address: true
+
+  xlnx,tx-ping-pong:
+    type: boolean
+    description: hardware supports tx ping pong buffer.
+
+  xlnx,rx-ping-pong:
+    type: boolean
+    description: hardware supports rx ping pong buffer.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - phy-handle
+
+additionalProperties: false
+
+examples:
+  - |
+    axi_ethernetlite_1: ethernet@40e00000 {
+        compatible = "xlnx,xps-ethernetlite-3.00.a";
+        reg = <0x40e00000 0x10000>;
+        interrupt-parent = <&axi_intc_1>;
+        interrupts = <1>;
+        local-mac-address = [00 00 00 00 00 00];
+        phy-handle = <&phy0>;
+        xlnx,rx-ping-pong;
+        xlnx,tx-ping-pong;
+    };