drm/amdgpu/display: fix the build when CONFIG_DRM_AMD_DC_DCN is not set

Need to protect some DSC functions.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -3926,7 +3926,9 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
 	bool scale = dm_state ? (dm_state->scaling != RMX_OFF) : false;
 	int mode_refresh;
 	int preferred_refresh = 0;
+#if defined(CONFIG_DRM_AMD_DC_DCN)
 	struct dsc_dec_dpcd_caps dsc_caps;
+#endif
 	uint32_t link_bandwidth_kbps;
 
 	struct dc_sink *sink = NULL;
@@ -4005,12 +4007,15 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
 	stream->timing.flags.DSC = 0;
 
 	if (aconnector->dc_link && sink->sink_signal == SIGNAL_TYPE_DISPLAY_PORT) {
+#if defined(CONFIG_DRM_AMD_DC_DCN)
 		dc_dsc_parse_dsc_dpcd(aconnector->dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.raw,
 				      aconnector->dc_link->dpcd_caps.dsc_caps.dsc_ext_caps.raw,
 				      &dsc_caps);
+#endif
 		link_bandwidth_kbps = dc_link_bandwidth_kbps(aconnector->dc_link,
 							     dc_link_get_link_cap(aconnector->dc_link));
 
+#if defined(CONFIG_DRM_AMD_DC_DCN)
 		if (dsc_caps.is_dsc_supported)
 			if (dc_dsc_compute_config(aconnector->dc_link->ctx->dc->res_pool->dscs[0],
 						  &dsc_caps,
@@ -4019,6 +4024,7 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
 						  &stream->timing,
 						  &stream->timing.dsc_cfg))
 				stream->timing.flags.DSC = 1;
+#endif
 	}
 
 	update_stream_scaling_settings(&mode, dm_state, stream);