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

Nintendo-Wii

modulename: wii.ko

configname: CONFIG_WII

Linux Kernel Configuration
└─>Nintendo-Wii
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
Select WII if configuring for the Nintendo Wii.
More information at: <http://gc-linux.sourceforge.net/>

source code:
/arch/powerpc/platforms/embedded6xx/