drm/i915/dp: Add DP tunnel atomic state and check BW limit

drm/i915/dp: Add DP tunnel atomic state and check BW limit

Add the atomic state during a modeset required to enable the DP tunnel
BW allocation mode on links where such a tunnel was detected. This state
applies to an already enabled output, the state added for a newly
enabled output will be computed and added/cleared to/from the atomic
state in a follow-up patch.

v2:
- s/old_crtc_state/crtc_state in intel_crtc_duplicate_state().
- Move intel_dp_tunnel_atomic_cleanup_inherited_state() to a follow-up
  patch adding the corresponding state. (Ville)
- Move intel_dp_tunnel_atomic_clear_stream_bw() to a follow-up
  patch adding the corresponding state.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240220211841.448846-14-imre.deak@intel.com