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

Support for Bus Watcher statistics

modulename: bus_watcher.ko

configname: CONFIG_SIBYTE_BUS_WATCHER

Linux Kernel Configuration
└─>Support for Bus Watcher statistics
In linux kernel since version 2.6.12  
Handle and keep statistics on the bus error interrupts (COR_ECC,
BAD_ECC, IO_BUS).

source code:
arch/mips/sibyte/common/bus_watcher.c