default or selected kernelversion does not have config value CONFIG_CZNIC_PLATFORMS.
Result is shown for kernelversion 6.12-rc1

Platform support for CZ.NIC's Turris hardware

configname: CONFIG_CZNIC_PLATFORMS

Linux Kernel Configuration
└─>Device Drivers
└─>Platform support for CZ.NIC's Turris hardware
In linux kernel since version 6.11 (release Date: 2024-09-15)  
Say Y here to be able to choose driver support for CZ.NIC's Turris
devices. This option alone does not add any kernel code.