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

CONFIG_SYS_SUPPORTS_CMT (not configurable)

configname: CONFIG_SYS_SUPPORTS_CMT

Linux/SuperH Kernel Configuration
└─>SYS_SUPPORTS_CMT
In linux kernel since version 2.6.30 (release Date: 2009-06-09)  
is selected by
CONFIG_SH_TIMER_CMT