CONFIG_SIBYTE_BCM1125H is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_SIBYTE_BCM1125H (not configurable)

configname: CONFIG_SIBYTE_BCM1125H

Linux/MIPS Kernel Configuration
└─>Machine selection
└─>SIBYTE_BCM1125H
In linux kernel since version 2.6.12