default or selected kernelversion does not have config value CONFIG_ARM_SMMU_V3_KUNIT_TEST.
Result is shown for kernelversion 6.9.8

KUnit tests for arm-smmu-v3 driver

modulename: arm-smmu-v3-test.ko

configname: CONFIG_ARM_SMMU_V3_KUNIT_TEST

Linux Kernel Configuration
└─>Device Drivers
└─>IOMMU Hardware Support
└─>KUnit tests for arm-smmu-v3 driver
In linux kernel since version 4.19.318 (release Date: 2024-07-18)  
Enable this option to unit-test arm-smmu-v3 driver functions.

If unsure, say N.

source code:
drivers/iommu/arm//arm-smmu-v3/arm-smmu-v3-test.c