CONFIG_PPC32 is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

CONFIG_PPC32 (not configurable)

modulename: bootx_init.ko

and/or

sys_ppc32.ko

and/or

entry_32.ko

and/or

strlen_32.ko

and/or

div64.ko

and/or

relocate_32.ko

and/or

init_32.ko

configname: CONFIG_PPC32

Linux Kernel Configuration
└─>PPC32
In linux kernel since version 2.6.15 (release Date: 2006-01-02)  
source code:
/arch/powerpc/platforms/powermac/bootx_init.c