dt-bindings: net: phy: Document support for LEDs node

Document support for LEDs node in phy and add an example for it.
PHY LED will have to match led pattern and should be treated as a
generic led.

Signed-off-by: Christian Marangi <[e-mail]>
Reviewed-by: Andrew Lunn <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

Documentation/devicetree/bindings/net/ethernet-phy.yaml

···
       PHY's that have configurable TX internal delays. If this property is
       present then the PHY applies the TX delay.
 
+  leds:
+    type: object
+
+    properties:
+      '#address-cells':
+        const: 1
+
+      '#size-cells':
+        const: 0
+
+    patternProperties:
+      '^led@[a-f0-9]+$':
+        $ref: /schemas/leds/common.yaml#
+
+        properties:
+          reg:
+            maxItems: 1
+            description:
+              This define the LED index in the PHY or the MAC. It's really
+              driver dependent and required for ports that define multiple
+              LED for the same port.
+
+        required:
+          - reg
+
+        unevaluatedProperties: false
+
+    additionalProperties: false
+
 required:
   - reg
 
···
 
 examples:
   - |
+    #include <dt-bindings/leds/common.h>
+
     ethernet {
         #address-cells = <1>;
         #size-cells = <0>;
···
             reset-gpios = <&gpio1 4 1>;
             reset-assert-us = <1000>;
             reset-deassert-us = <2000>;
+
+            leds {
+                #address-cells = <1>;
+                #size-cells = <0>;
+
+                led@0 {
+                    reg = <0>;
+                    color = <LED_COLOR_ID_WHITE>;
+                    function = LED_FUNCTION_LAN;
+                    default-state = "keep";
+                };
+            };
         };
     };