default or selected kernelversion does not have config value CONFIG_SPI_KSPI2.
Result is shown for kernelversion 6.6.78

Support for KEBA SPI master type 2 hardware

modulename: spi-kspi2.ko

configname: CONFIG_SPI_KSPI2

Linux Kernel Configuration
└─>Device Drivers
└─>SPI support
└─>Support for KEBA SPI master type 2 hardware
In linux kernel since version 6.6.78 (release Date: 2025-02-17)  
This driver supports KEBA SPI master type 2 FPGA implementation,
as found on CP500 devices for example.

This driver can also be built as a module. If so, the module
will be called spi-kspi2.

source code: