CONFIG_MIPS32 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_MIPS32 (not configurable)

modulename: ioremap.ko

and/or

module-elf32.ko

and/or

scall32-o32.ko

configname: CONFIG_MIPS32

Linux Kernel Configuration
└─>MIPS32
In linux kernel since version 2.6.12  
source code: