CONFIG_M5206eC3 is not available for thedefaultarchitecture x86.
Result is shown for architecture m68k

Motorola M5206eC3 board support

configname: CONFIG_M5206eC3

Linux Kernel Configuration
└─>Motorola M5206eC3 board support
In linux kernel since version 2.6.12  
Support for the Motorola M5206eC3 board.

depends
CONFIG_M5206e