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

Enable optimized CRC implementations

configname: CONFIG_CRC_OPTIMIZATIONS

Linux Kernel Configuration
└─>Library routines
└─>Enable optimized CRC implementations
In linux kernel since version 6.6.78 (release Date: 2025-02-17)  
Disabling this option reduces code size slightly by disabling the
architecture-optimized implementations of any CRC variants that are
enabled. CRC checksumming performance may get much slower.

Keep this enabled unless you're really trying to minimize the size of
the kernel.