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

Stallion multiport serial support

configname: CONFIG_STALDRV

Linux Kernel Configuration
└─>Device Drivers
└─>Character devices
└─>Stallion multiport serial support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Stallion cards give you many serial ports. You would need something
like this to connect more than two modems to your Linux box, for
instance in order to become a dial-in server. If you say Y here,
you will be asked for your specific card model in the next
questions. Make sure to read Documentation/serial/stallion.txt
in this case. If you have never heard about all this, it's safe to
say N.