CONFIG_TILEGX is not available for thedefaultarchitecture x86.
Result is shown for architecture tile

Building for TILE-Gx (64-bit) processor

modulename: futex_64.ko

configname: CONFIG_TILEGX

Linux Kernel Configuration
└─>Building for TILE-Gx (64-bit) processor
In linux kernel since version 2.6.36 (release Date: 2010-10-20)  

depends
 or CONFIG_EXPERIMENTAL