default or selected kernelversion does not have config value CONFIG_SND_BF5XX_SOC_AD1938.
Result is shown for kernelversion 5.4.194
SoC AD1938 Audio support for Blackfin
modulename: snd-ad1938.ko
configname: CONFIG_SND_BF5XX_SOC_AD1938
Linux Kernel Configuration
└─>Device Drivers
└─>Sound card support
└─>Advanced Linux Sound Architecture
└─>ALSA for SoC audio support
└─>SoC AD1938 Audio support for Blackfin
In linux kernel since version 2.6.32 (release Date: 2009-12-02)
Say Y if you want to add support for AD1938 codec on Blackfin.