dt-bindings: phy: zynqmp-psgtr: Fix example's numbers of cells in reg

The DT examples are by default compiled in a parent that has
 #address-cells and #size-cells both set to 1. Fix the example
accordingly, even if it doesn't match the actual hardware, as this is
the recommended practice for DT bindings examples.

Fixes: cea0f76a ("dt-bindings: phy: Add DT bindings for Xilinx ZynqMP PSGTR PHY")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://lore.kernel.org/r/20200701134853.30656-1-laurent.pinchart@ideasonboard.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/xlnx,zynqmp-psgtr.yaml

@@ -94,8 +94,8 @@ examples:
   - |
     phy: phy@fd400000 {
         compatible = "xlnx,zynqmp-psgtr-v1.1";
-        reg = <0x0 0xfd400000 0x0 0x40000>,
-              <0x0 0xfd3d0000 0x0 0x1000>;
+        reg = <0xfd400000 0x40000>,
+              <0xfd3d0000 0x1000>;
         reg-names = "serdes", "siou";
         clocks = <&refclks 3>, <&refclks 2>, <&refclks 0>;
         clock-names = "ref1", "ref2", "ref3";