CONFIG_MCPU32 is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

CONFIG_MCPU32 (not configurable)

configname: CONFIG_MCPU32

Linux Kernel Configuration
└─>MCPU32
In linux kernel since version 3 (release Date: 2011-07-21)  
The Freescale (was then Motorola) CPU32 is a CPU core that is
based on the 68020 processor. For the most part it is used in
System-On-Chip parts, and does not contain a paging MMU.