dt-bindings: usb: gpio-sbu-mux: Make 'enable-gpios' optional

The enable gpio is not required when the SBU mux is used only for
orientation, make enable-gpios required only for alternate mode
switch use case.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20240603083558.9629-2-francesco@dolcini.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/gpio-sbu-mux.yaml

@@ -44,13 +44,18 @@ properties:
 
 required:
   - compatible
-  - enable-gpios
   - select-gpios
   - orientation-switch
   - port
 
 allOf:
   - $ref: usb-switch.yaml#
+  - if:
+      required:
+        - mode-switch
+    then:
+      required:
+        - enable-gpios
 
 additionalProperties: false