default or selected kernelversion does not have config value CONFIG_DRM_STI_FBDEV.
Result is shown for kernelversion 5.4.229
DRM frame buffer device for STMicroelectronics SoC stiH41x Serie
configname: CONFIG_DRM_STI_FBDEV
Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Direct Rendering Manager
└─>DRM frame buffer device for STMicroelectronics SoC stiH41x Serie
In linux kernel since version 3.17 (release Date: 2014-10-05)
Choose this option to enable FBDEV on top of DRM for STM stiH41x chipset