dt-bindings: leds: Fix reference to definition of default-state

At least since the YAML conversion, the default-state property is
described in leds/common.yaml, so there's no need to point to another
file for its definition.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230814163116.1696092-1-j.neuschaefer@gmx.net
Signed-off-by: Lee Jones <lee@kernel.org>

Documentation/devicetree/bindings/leds/common.yaml

@@ -83,8 +83,7 @@ properties:
       - enum:
             # LED will act as a back-light, controlled by the framebuffer system
           - backlight
-            # LED will turn on (but for leds-gpio see "default-state" property in
-            # Documentation/devicetree/bindings/leds/leds-gpio.yaml)
+            # LED will turn on (see also "default-state" property)
           - default-on
             # LED "double" flashes at a load average based rate
           - heartbeat