default or selected kernelversion does not have config value CONFIG_CRYPTO_LIB_SM4.
Result is shown for kernelversion 6.9.9

CONFIG_CRYPTO_LIB_SM4 (not configurable)

modulename: libsm4.ko

configname: CONFIG_CRYPTO_LIB_SM4

Linux Kernel Configuration
└─>Library routines
└─>Crypto library routines
└─>CRYPTO_LIB_SM4
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
source code:
lib/crypto/