drm/amd/display: fix dml max voltage state

Gabe's formula sometimes uses values from non-existent 'unsupported'
state to do validation.

This change adds this extra state so validation can work correctly.
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -113,7 +113,8 @@ struct _vcs_dpi_soc_bounding_box_st {
 	int use_urgent_burst_bw;
 	double max_hscl_ratio;
 	double max_vscl_ratio;
-	struct _vcs_dpi_voltage_scaling_st clock_limits[7];
+	unsigned int num_states;
+	struct _vcs_dpi_voltage_scaling_st clock_limits[8];
 };
 
 struct _vcs_dpi_ip_params_st {