Revert "drm/i915/display: Drop FIXME about turn off infoframes"

Looks this FIXME is still valid as we need a way to tell LSPCON to
stop sending infoframes, so reverting it.

This reverts commit 3f409e4.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210610194527.84997-1-jose.souza@intel.com

drivers/gpu/drm/i915/display/intel_ddi.c

@@ -2810,6 +2810,7 @@ static void intel_ddi_pre_enable(struct intel_atomic_state *state,
 					conn_state);
 
 		/* FIXME precompute everything properly */
+		/* FIXME how do we turn infoframes off again? */
 		if (dig_port->lspcon.active && dig_port->dp.has_hdmi_sink)
 			dig_port->set_infoframes(encoder,
 						 crtc_state->has_infoframe,