drm/amd/display: Enable dp_hdmi21_pcon support

[Why]
It is not enabled for DCN3.0.1, 3.0.2, 3.0.3.

[How]
Add `dc->caps.dp_hdmi21_pcon_support = true` to these DCN versions.
Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: David Galiffi <David.Galiffi@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn301/dcn301_resource.c

@@ -1493,6 +1493,8 @@ static bool dcn301_resource_construct(
 	dc->caps.color.mpc.ogam_rom_caps.hlg = 0;
 	dc->caps.color.mpc.ocsc = 1;
 
+	dc->caps.dp_hdmi21_pcon_support = true;
+
 	/* read VBIOS LTTPR caps */
 	if (ctx->dc_bios->funcs->get_lttpr_caps) {
 		enum bp_result bp_query_result;

drivers/gpu/drm/amd/display/dc/dcn302/dcn302_resource.c

@@ -1281,6 +1281,8 @@ static bool dcn302_resource_construct(
 	dc->caps.color.mpc.ogam_rom_caps.hlg = 0;
 	dc->caps.color.mpc.ocsc = 1;
 
+	dc->caps.dp_hdmi21_pcon_support = true;
+
 	/* read VBIOS LTTPR caps */
 	if (ctx->dc_bios->funcs->get_lttpr_caps) {
 		enum bp_result bp_query_result;

drivers/gpu/drm/amd/display/dc/dcn303/dcn303_resource.c

@@ -1212,6 +1212,8 @@ static bool dcn303_resource_construct(
 	dc->caps.color.mpc.ogam_rom_caps.hlg = 0;
 	dc->caps.color.mpc.ocsc = 1;
 
+	dc->caps.dp_hdmi21_pcon_support = true;
+
 	/* read VBIOS LTTPR caps */
 	if (ctx->dc_bios->funcs->get_lttpr_caps) {
 		enum bp_result bp_query_result;