dt-bindings: fsl,fpga-qixis: describe the gpio child node found on LS1046AQDS

Extend the list of accepted child nodes with the QIXIS FPGA based GPIO
controller and explicitly list its compatible string
fsl,ls1046aqds-fpga-gpio-stat-pres2 as the only one accepted.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/board/fsl,fpga-qixis.yaml

@@ -57,6 +57,16 @@ patternProperties:
   '^mdio-mux@[a-f0-9,]+$':
     $ref: /schemas/net/mdio-mux-mmioreg.yaml
 
+  '^gpio@[0-9a-f]+$':
+    type: object
+    additionalProperties: true
+
+    properties:
+      compatible:
+        contains:
+          enum:
+            - fsl,ls1046aqds-fpga-gpio-stat-pres2
+
 required:
   - compatible
   - reg