default or selected kernelversion does not have config value CONFIG_DRM_DISPLAY_HELPER.
Result is shown for kernelversion 6.9.9

CONFIG_DRM_DISPLAY_HELPER (not configurable)

modulename: drm_display_helper.ko

configname: CONFIG_DRM_DISPLAY_HELPER

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)
└─>DRM_DISPLAY_HELPER
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
DRM helpers for display adapters.

source code:
drivers/gpu/drm//display/