drm/i915/dp_tunnel: Don't update tunnel state during system resume

drm/i915/dp_tunnel: Don't update tunnel state during system resume

During system resume, restoring the pre-suspend display state must not
fail. This requires preserving the sink capabilities from before
suspend, including the available link bandwidth.

If these capabilities are not preserved, the restore modeset may fail,
either due to a missing sink capability or insufficient link bandwidth
for the restored mode.

When the sink is connected through a DP tunnel, prevent such capability
changes by skipping tunnel state updates during resume. This also avoids
updating the sink state via the tunnel while it is being resumed.

Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260219182823.926702-2-imre.deak@intel.com