CONFIG_ROMKERNEL is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

ROM

modulename: head_rom.ko

configname: CONFIG_ROMKERNEL

Kernel executes from
└─>ROM
In linux kernel since version 2.6.12  
The kernel will be resident in FLASH/ROM when running. This is
often referred to as Execute-in-Place (XIP), since the kernel
code executes from the position it is stored in the FLASH/ROM.

depends
CONFIG_ROM