spi: dt-bindings: fsl-lpspi: Add i.MX94 support

Add compatible string "fsl,imx94-spi" for the i.MX94 chip, which is
backward compatible with i.MX7ULP. Set it to fall back to
"fsl,imx7ulp-spi".

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20250306170954.242707-1-Frank.Li@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: nxpfrankli

Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml

@@ -24,6 +24,7 @@ properties:
           - enum:
               - fsl,imx8ulp-spi
               - fsl,imx93-spi
+              - fsl,imx94-spi
               - fsl,imx95-spi
           - const: fsl,imx7ulp-spi
   reg: