CONFIG_HEART_BEAT is not available for thedefaultarchitecture x86.
Result is shown for architecture microblaze
default or selected kernelversion does not have config value CONFIG_HEART_BEAT.
Result is shown for kernelversion 6.7-rc3

Heart beat function for kernel

modulename: heartbeat.ko

configname: CONFIG_HEART_BEAT

Linux Kernel Configuration
└─>Kernel hacking
└─>Heart beat function for kernel
In linux kernel since version 2.6.30 (release Date: 2009-06-09)  
This option turns on/off heart beat kernel functionality.
First GPIO node is taken.

source code: