default or selected kernelversion does not have config value CONFIG_DRM_AMD_DC_FBC.
Result is shown for kernelversion 6.4.14

AMD FBC - Enable Frame Buffer Compression


Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)
└─>Display Engine Configuration
└─>AMD FBC - Enable Frame Buffer Compression
In linux kernel since version 4.9.8 (release Date: 2017-02-04)  
Choose this option if you want to use frame buffer compression
This is a power optimisation feature, check its availability
on your hardware before enabling this option.