CONFIG_FIT_IMAGE_FDT_LUTON is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Include FDT for Microsemi Luton development platforms

configname: CONFIG_FIT_IMAGE_FDT_LUTON

Linux Kernel Configuration
└─>Include FDT for Microsemi Luton development platforms
In linux kernel since version 5.2 (release Date: 2019-07-07)  
Enable this to include the FDT for the Luton development platforms
from Microsemi in the FIT kernel image.
This requires u-boot on the platform.