CONFIG_KERNEL_ABI_DEFAULT is not available for thedefaultarchitecture x86.
Result is shown for architecture xtensa

Default ABI

configname: CONFIG_KERNEL_ABI_DEFAULT

Kernel ABI
└─>Default ABI
In linux kernel since version 5.2 (release Date: 2019-07-07)  
Select this option to compile kernel code with the default ABI
selected for the toolchain.
Normally cores with windowed registers option use windowed ABI and
cores without it use call0 ABI.