drm/amd/display: Add num_active_wb to DML

Signed-off-by: NEric Bernstein <eric.bernstein@amd.com>
Reviewed-by: NTony Cheng <Tony.Cheng@amd.com>
Acked-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/display_mode_structs.h

@@ -224,6 +224,7 @@ struct	_vcs_dpi_display_output_params_st	{
 	int	output_bpp;
 	int	dsc_enable;
 	int	wb_enable;
+	int	num_active_wb;
 	int	opp_input_bpc;
 	int	output_type;
 	int	output_format;