drm/amd/display: Use hardware sequencer functions for PG control

[Why & How]
These can differ per ASIC or not be present. Don't call the dcn20 ones
directly but rather the ones defined by the ASIC init table.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Anson Jacob <anson.jacob@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -647,8 +647,13 @@ static void power_on_plane(
 	if (REG(DC_IP_REQUEST_CNTL)) {
 		REG_SET(DC_IP_REQUEST_CNTL, 0,
 				IP_REQUEST_EN, 1);
-		hws->funcs.dpp_pg_control(hws, plane_id, true);
-		hws->funcs.hubp_pg_control(hws, plane_id, true);
+
+		if (hws->funcs.dpp_pg_control)
+			hws->funcs.dpp_pg_control(hws, plane_id, true);
+
+		if (hws->funcs.hubp_pg_control)
+			hws->funcs.hubp_pg_control(hws, plane_id, true);
+
 		REG_SET(DC_IP_REQUEST_CNTL, 0,
 				IP_REQUEST_EN, 0);
 		DC_LOG_DEBUG(
@@ -1082,8 +1087,13 @@ void dcn10_plane_atomic_power_down(struct dc *dc,
 	if (REG(DC_IP_REQUEST_CNTL)) {
 		REG_SET(DC_IP_REQUEST_CNTL, 0,
 				IP_REQUEST_EN, 1);
-		hws->funcs.dpp_pg_control(hws, dpp->inst, false);
-		hws->funcs.hubp_pg_control(hws, hubp->inst, false);
+
+		if (hws->funcs.dpp_pg_control)
+			hws->funcs.dpp_pg_control(hws, dpp->inst, false);
+
+		if (hws->funcs.hubp_pg_control)
+			hws->funcs.hubp_pg_control(hws, hubp->inst, false);
+
 		dpp->funcs->dpp_reset(dpp);
 		REG_SET(DC_IP_REQUEST_CNTL, 0,
 				IP_REQUEST_EN, 0);

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

@@ -1062,8 +1062,13 @@ static void dcn20_power_on_plane(
 	if (REG(DC_IP_REQUEST_CNTL)) {
 		REG_SET(DC_IP_REQUEST_CNTL, 0,
 				IP_REQUEST_EN, 1);
-		dcn20_dpp_pg_control(hws, pipe_ctx->plane_res.dpp->inst, true);
-		dcn20_hubp_pg_control(hws, pipe_ctx->plane_res.hubp->inst, true);
+
+		if (hws->funcs.dpp_pg_control)
+			hws->funcs.dpp_pg_control(hws, pipe_ctx->plane_res.dpp->inst, true);
+
+		if (hws->funcs.hubp_pg_control)
+			hws->funcs.hubp_pg_control(hws, pipe_ctx->plane_res.hubp->inst, true);
+
 		REG_SET(DC_IP_REQUEST_CNTL, 0,
 				IP_REQUEST_EN, 0);
 		DC_LOG_DEBUG(