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

Lantiq based platforms

modulename: fixup-lantiq.ko

configname: CONFIG_LANTIQ

System type
└─>Lantiq based platforms
In linux kernel since version 3 (release Date: 2011-07-21)  
source code:
arch/mips/pci/fixup-lantiq.c

is selected by
CONFIG_MTD_NAND_XWAY