CONFIG_ARCH_FORTUNET is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_FORTUNET.
Result is shown for kernelversion 6.2.5

FORTUNET

modulename: fortunet.ko

and/or

board-fortunet.ko

configname: CONFIG_ARCH_FORTUNET

Linux Kernel Configuration
└─>CLPS711X/EP721X Implementations
└─>FORTUNET
In linux kernel since version 2.6.12  
source code:
arch/arm/mach-clps711x/fortunet.c