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

CONFIG_SYS_SUPPORTS_MIPS_CMP (not configurable)

configname: CONFIG_SYS_SUPPORTS_MIPS_CMP

Linux Kernel Configuration
└─>Kernel type
└─>SYS_SUPPORTS_MIPS_CMP
In linux kernel since version 2.6.27 (release Date: 2008-10-09)  
is selected by
CONFIG_MIPS_CMP