dt-bindings: gpio: xilinx: Fix node address in gpio

Node address doesn't match reg property which is not correct.

Fixes: ba96b2e7 ("dt-bindings: gpio: gpio-xilinx: Convert Xilinx axi gpio binding to YAML")
Signed-off-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Documentation/devicetree/bindings/gpio/xlnx,gpio-xilinx.yaml

@@ -126,7 +126,7 @@ examples:
   - |
     #include <dt-bindings/interrupt-controller/arm-gic.h>
 
-        gpio@e000a000 {
+        gpio@a0020000 {
             compatible = "xlnx,xps-gpio-1.00.a";
             reg = <0xa0020000 0x10000>;
             #gpio-cells = <2>;