CONFIG_MACH_KEV7A400 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_MACH_KEV7A400.
Result is shown for kernelversion 5.4.69

KEV7A400

modulename: arch-kev7a400.ko

configname: CONFIG_MACH_KEV7A400

Linux Kernel Configuration
└─>LH7A40X Implementations
└─>KEV7A400
In linux kernel since version 2.6.12  
Say Y here if you are using the Sharp KEV7A400 development
board. This hardware is discontinued, so I'd be very
surprised if you wanted this option.

source code: