CONFIG_CLKSRC_I8253 (not configurable)

modulename: i8253.ko

configname: CONFIG_CLKSRC_I8253

Linux Kernel Configuration
└─>Device Drivers
└─>CLKSRC_I8253
In linux kernel since version 3 (release Date: 2011-07-21)  
source code:
drivers/clocksource/i8253.c