Dear,
I am working on i.MX93 EVK and faceing the same issue either.
I had tried to boot from the dtb as mentioned in JorgeCas's reply.
If boot system with imx93-11x11-evk-lpspi.dts, I did see the device node, namely spidev0.0.
For booting with imx93-11x11-evk-lpspi-slave.dts, I can't see the device node spidev0.0 but can see the content changes in /sys/class/spi_slave.
My question is how to program with the spi slave without device node.
Any example code for the spi slave usage?