drm/i915/dmc: Don't enable any pipe DMC events

drm/i915/dmc: Don't enable any pipe DMC events

The pipe DMC seems to be making a mess of things in ADL. Various weird
symptoms have been observed such as missing vblank irqs, typicalle
happening when using multiple displays.

Keep all pipe DMC event handlers disabled until needed (which is never
atm). This is also what Windows does on ADL+.

We can also drop DG2 from disable_all_flip_queue_events() since
on DG2 the pipe DMC is the one that handles the flip queue events.

Cc: stable@vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8685
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231211213750.27109-2-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>