bindings: ethernet: fix typo in infineon,xmc4xxx-ethernet

Corrected the description for the rxd3-port-ctrl property as there was a
typo.

Signed-off-by: Benjamin Cabé <[email protected]>

Author: kartben

dts/bindings/ethernet/infineon,xmc4xxx-ethernet.yaml

@@ -51,7 +51,7 @@ properties:
 
   rxd3-port-ctrl:
     type: string
-    description: Receive bit 2 (rxd2) signal GPIO connection. Only used for MII interface.
+    description: Receive bit 3 (rxd3) signal GPIO connection. Only used for MII interface.
     enum:
       - "P5_9"
       - "P6_3"