dt-bindings: serial: fsl-lpuart: support i.MX94

Add compatible string "fsl,imx94-lpuart" for the i.MX94 chip, which is
backward compatible with i.MX8ULP. Set it to fall back to
"fsl,imx8ulp-lpuart".

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250306171052.244548-1-Frank.Li@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: nxpfrankli

Documentation/devicetree/bindings/serial/fsl-lpuart.yaml

@@ -30,6 +30,7 @@ properties:
       - items:
           - enum:
               - fsl,imx93-lpuart
+              - fsl,imx94-lpuart
               - fsl,imx95-lpuart
           - const: fsl,imx8ulp-lpuart
           - const: fsl,imx7ulp-lpuart