dt-bindings: serial: fsl-linflexuart: add compatible for S32G3

Add a compatible string for the uart binding of NXP S32G3 platforms. Here
we use "s32v234-linflexuart" as fallback since the current linflexuart
driver can still work on S32G3.
Signed-off-by: Wadim Mueller <wafgo01@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240324214329.29988-3-wafgo01@gmail.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml

@@ -23,7 +23,9 @@ properties:
     oneOf:
       - const: fsl,s32v234-linflexuart
       - items:
-          - const: nxp,s32g2-linflexuart
+          - enum:
+              - nxp,s32g2-linflexuart
+              - nxp,s32g3-linflexuart
           - const: fsl,s32v234-linflexuart
 
   reg: