Enable DP tunnel support

configname: CONFIG_DRM_I915_DP_TUNNEL

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Enable DP tunnel support
In linux kernel since version 4.19.314 (release Date: 2024-05-17)  
Choose this option to detect DP tunnels and enable the Bandwidth
Allocation mode for such tunnels. This allows using the maximum
resolution allowed by the link BW on all displays sharing the
link BW, for instance on a Thunderbolt link.

If in doubt, say "Y".