CONFIG_MIPS_NILE4 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_MIPS_NILE4 (not configurable)

modulename: ops-nile4.ko

configname: CONFIG_MIPS_NILE4

Linux Kernel Configuration
└─>MIPS_NILE4
In linux kernel since version 2.6.12  
source code:
arch/mips/pci/ops-nile4.c