dt-bindings: soundwire: fix example

As wsa881x schema mentions #sound-dai-cells as required property,
so update soundwire-controller.yaml example so that dt_bindings_check
does not fail as below:

Documentation/devicetree/bindings/soundwire/soundwire-controller.example.dt.yaml:
speaker@0,1: '#sound-dai-cells' is a required property
Documentation/devicetree/bindings/soundwire/soundwire-controller.example.dt.yaml:
speaker@0,2: '#sound-dai-cells' is a required property

Reported-by: Rob Herring <[email protected]>
Signed-off-by: Srinivas Kandagatla <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>

Author: Srinivas-Kandagatla

Documentation/devicetree/bindings/soundwire/soundwire-controller.yaml

@@ -69,13 +69,15 @@ examples:
             reg = <0 1>;
             powerdown-gpios = <&wcdpinctrl 2 0>;
             #thermal-sensor-cells = <0>;
+            #sound-dai-cells = <0>;
         };
 
         speaker@0,2 {
             compatible = "sdw10217201000";
             reg = <0 2>;
             powerdown-gpios = <&wcdpinctrl 2 0>;
             #thermal-sensor-cells = <0>;
+            #sound-dai-cells = <0>;
         };
     };