default or selected kernelversion does not have config value CONFIG_USB_SERIAL_SIEMENS_MPI.
Result is shown for kernelversion 6.2.5

USB Siemens MPI driver

modulename: siemens_mpi.ko

configname: CONFIG_USB_SERIAL_SIEMENS_MPI

Linux Kernel Configuration
└─>Device Drivers
└─>USB support
└─>USB Serial Converter support
└─>USB Siemens MPI driver
In linux kernel since version 2.6.29 (release Date: 2009-03-23)  
Say M here if you want to use a Siemens USB/MPI adapter.

To compile this driver as a module, choose M here: the
module will be called siemens_mpi.

source code: