CONFIG_DDB5477 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips
default or selected kernelversion does not have config value CONFIG_DDB5477.
Result is shown for kernelversion 5.4.123

Support for NEC DDB Vrc-5477

modulename: fixup-ddb5477.ko

configname: CONFIG_DDB5477

Linux/MIPS Kernel Configuration
└─>Machine selection
└─>Support for NEC DDB Vrc-5477
In linux kernel since version 2.6.12  
This enables support for the R5432-based NEC DDB Vrc-5477,
or Rockhopper/SolutionGear boards with R5432/R5500 CPUs.

Features : kernel debugging, serial terminal, NFS root fs, on-board
ether port USB, AC97, PCI, etc.

source code: