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>