CONFIG_SIBYTE_CRHONE is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

BCM91125C-CRhone

configname: CONFIG_SIBYTE_CRHONE

BCM1xxx SOC-based board
└─>BCM91125C-CRhone
In linux kernel since version 2.6.12  

depends
 or CONFIG_EXPERIMENTAL