dt-bindings: misc: Describe FPC202 LED features

The FPC202 dual port controller has 20 regular GPIO lines and 8 special
GPIO lines with LED features. Each one of these "LED GPIOs" can output PWM
and blink signals.

Describe these special-purpose GPIO lines.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
Link: https://patch.msgid.link/20260331-fpc202-leds-v3-2-74b173537d42@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/misc/ti,fpc202.yaml

@@ -53,6 +53,22 @@ patternProperties:
 
     unevaluatedProperties: false
 
+  "^led@1[4-b]$":
+    $ref: /schemas/leds/common.yaml#
+    description: Output GPIO line with advanced LED features enabled.
+
+    properties:
+      reg:
+        minimum: 0x14
+        maximum: 0x1b
+        description:
+          GPIO line ID
+
+    required:
+      - reg
+
+    unevaluatedProperties: false
+
 required:
   - compatible
   - reg
@@ -89,6 +105,11 @@ examples:
                 #size-cells = <0>;
                 reg = <1>;
             };
+
+            led@14 {
+                reg = <0x14>;
+                label = "phy0:green:indicator";
+            };
         };
     };
 ...