CONFIG_S5P_DEV_FIMC3 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_S5P_DEV_FIMC3.
Result is shown for kernelversion 6.5.1

CONFIG_S5P_DEV_FIMC3 (not configurable)

configname: CONFIG_S5P_DEV_FIMC3

Linux Kernel Configuration
└─>S5P_DEV_FIMC3
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
Compile in platform device definitions for FIMC controller 3