default or selected kernelversion does not have config value CONFIG_DEBUG_BLK_CGROUP.
Result is shown for kernelversion 5.4.194

CONFIG_DEBUG_BLK_CGROUP (not configurable)

configname: CONFIG_DEBUG_BLK_CGROUP

Linux Kernel Configuration
└─>Enable the block layer
└─>DEBUG_BLK_CGROUP
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
Enable some debugging help. Currently it stores the cgroup path
in the blk group which can be used by cfq for tracing various
group related activity.