drm/amd/display: Use config flag to disable dmcu obj creation

[Why]
When dmcub is the default we no longer wish to create the psr and dmcu
objects. Currently a dc debug flag is used to implement this, but these
flags aren't populated until after dcn21_resource_construct is called.
This means the dmcub objects will never be created. Therefore we must
use a dc config flag, which is populated before dc resource construct.

[How]
Add a dc config flag.
Signed-off-by: Wyatt Wood <wyatt.wood@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -230,7 +230,7 @@ struct dc_config {
 	bool forced_clocks;
 	bool disable_extended_timeout_support; // Used to disable extended timeout and lttpr feature as well
 	bool multi_mon_pp_mclk_switch;
-	bool psr_on_dmub;
+	bool disable_dmcu;
 };
 
 enum visual_confirm {

drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c

@@ -993,7 +993,7 @@ static void dcn21_resource_destruct(struct dcn21_resource_pool *pool)
 	}
 
 	if (pool->base.abm != NULL) {
-		if (pool->base.abm->ctx->dc->debug.disable_dmcu)
+		if (pool->base.abm->ctx->dc->config.disable_dmcu)
 			dmub_abm_destroy(&pool->base.abm);
 		else
 			dce_abm_destroy(&pool->base.abm);
@@ -1846,7 +1846,7 @@ static bool dcn21_resource_construct(
 		goto create_fail;
 	}
 
-	if (!dc->debug.disable_dmcu) {
+	if (!dc->config.disable_dmcu) {
 		pool->base.dmcu = dcn21_dmcu_create(ctx,
 				&dmcu_regs,
 				&dmcu_shift,
@@ -1858,7 +1858,7 @@ static bool dcn21_resource_construct(
 		}
 	}
 
-	if (dc->debug.disable_dmcu) {
+	if (dc->config.disable_dmcu) {
 		pool->base.psr = dmub_psr_create(ctx);
 
 		if (pool->base.psr == NULL) {
@@ -1868,7 +1868,7 @@ static bool dcn21_resource_construct(
 		}
 	}
 
-	if (dc->debug.disable_dmcu)
+	if (dc->config.disable_dmcu)
 		pool->base.abm = dmub_abm_create(ctx,
 			&abm_regs,
 			&abm_shift,