default or selected kernelversion does not have config value CONFIG_SND_SOC_OF_SIMPLE.
Result is shown for kernelversion 5.4.229

CONFIG_SND_SOC_OF_SIMPLE (not configurable)

modulename: soc-of-simple.ko

configname: CONFIG_SND_SOC_OF_SIMPLE

Linux Kernel Configuration
└─>Device Drivers
└─>Sound card support
└─>Advanced Linux Sound Architecture
└─>ALSA for SoC audio support
└─>SND_SOC_OF_SIMPLE
In linux kernel since version 2.6.28 (release Date: 2008-12-24)  
source code:
sound/soc//fsl/soc-of-simple.c