drm/amdgpu/powerplay/vega10: enable mclk switching if monitors are synced

If DC has synced the displays, we can enable mclk switching to
save power.
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/hwmgr/vega10_hwmgr.c

@@ -3220,7 +3220,8 @@ static int vega10_apply_state_adjust_rules(struct pp_hwmgr *hwmgr,
 	if (hwmgr->display_config->num_display == 0)
 		disable_mclk_switching = false;
 	else
-		disable_mclk_switching = (hwmgr->display_config->num_display > 1) ||
+		disable_mclk_switching = ((1 < hwmgr->display_config->num_display) &&
+					  !hwmgr->display_config->multi_monitor_in_sync) ||
 			disable_mclk_switching_for_frame_lock ||
 			disable_mclk_switching_for_vr ||
 			force_mclk_high;