CONFIG_SIBYTE_CFE is not available for the selected architecture x86.
Result is shown for architecture mips
Booting from CFE
configname: CONFIG_SIBYTE_CFE
Linux Kernel Configuration
└─>Booting from CFE
In linux kernel since version 2.6.12 )
Make use of the CFE API for enumerating available memory,
controlling secondary CPUs, and possibly console output.
controlling secondary CPUs, and possibly console output.