drivers: spi: nxp: lpspi: use DT_DRV_COMPAT to fix native cs

As the other spi_nxp_lpspi driver source files use DT_DRV_COMPAT
and that is used to determine in spi_context.h if the gpio cs
code is used, it also have to be defined in spi_nxp_lpspi_common.c
so there is no mismatch and breaking of the driver.

Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>