drm/amd/display: Skip powerstate DC hw access if virtual dal

[Why]
On baco-enabled systems running virtual dal, can get set power
state when hw is not initialized

[How]
Skip DC hw part of setPowerState when hw not available
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Martin Leung <martin.leung@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Eryk Brol <eryk.brol@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -2969,6 +2969,9 @@ void dc_set_power_state(
 	struct kref refcount;
 	struct display_mode_lib *dml;
 
+	if (!dc->current_state)
+		return;
+
 	switch (power_state) {
 	case DC_ACPI_CM_POWER_STATE_D0:
 		dc_resource_state_construct(dc, dc->current_state);