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

Enable debugging the DP tunnel state

configname: CONFIG_DRM_DISPLAY_DEBUG_DP_TUNNEL_STATE

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Enable debugging the DP tunnel state
In linux kernel since version 4.19.314 (release Date: 2024-05-17)  
Enables debugging the DP tunnel manager's state, including the
consistency of all managed tunnels' reference counting and the state of
streams contained in tunnels.

If in doubt, say "N".