dt-bindings: serial: cdns: add Axiado AX3000 UART controller

Add binding for AX3000 UART controller. So far, no changes known,
so it can fallback to default compatible.

Reviewed-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Harshit Shah <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

Author: hshahaxiado

Documentation/devicetree/bindings/serial/cdns,uart.yaml

@@ -16,9 +16,10 @@ properties:
         items:
           - const: xlnx,xuartps
           - const: cdns,uart-r1p8
-      - description: UART controller for Zynq Ultrascale+ MPSoC
-        items:
-          - const: xlnx,zynqmp-uart
+      - items:
+          - enum:
+              - axiado,ax3000-uart
+              - xlnx,zynqmp-uart
           - const: cdns,uart-r1p12
 
   reg: