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

SPU file system

modulename: spu-base.ko

and/or

spufs.ko

configname: CONFIG_SPU_FS

Linux Kernel Configuration
└─>Cell Broadband Engine options
└─>SPU file system
In linux kernel since version 2.6.16 (release Date: 2006-03-19)  
The SPU file system is used to access Synergistic Processing
Units on machines implementing the Broadband Processor
Architecture.

source code:
/arch/powerpc/platforms/cell/
depends
CONFIG_PPC_CELL

is selected by
CONFIG_SPU_FS_64K_LS