CONFIG_M68328 is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

MC68328

modulename: m68328.ko

configname: CONFIG_M68328

Linux Kernel Configuration
└─>MC68328
In linux kernel since version 2.6.12  
Motorola 68328 processor support.

source code:
selects
CONFIG_M68000


is selected by
CONFIG_FB_68328