CONFIG_CPU_BIG_ENDIAN is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

Big Endian

modulename: sniprom.ko

configname: CONFIG_CPU_BIG_ENDIAN

Endianess selection
└─>Big Endian
In linux kernel since version 2.6.12  
source code:
arch/mips/sni/sniprom.c
depends
 or  NOT CONFIG_CPU_SH5

is selected by
CONFIG_PPC_PS3