board/lx2160aqds: Update the DSPI status fixup

board/lx2160aqds: Update the DSPI status fixup

The dts node of the DSPI controller in kernel is spi instead of dspi,
it is not correct if use "/soc/dspi@" to fix up the status of the dts
in kernel, so, modify it to "/soc/spi@".

The DSPI2 and I2C5 are muxed, and the status of DSPI2 node in kernel dts
default value is okay, So set the status of DSPI2 node in kernel dts to
disabled if it is muxed as I2C5.

Signed-off-by: Xiaowei Bao <xiaowei.bao@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>