drm/amd/display: fix dcn20 global sync dml param extraction

Currently the paremeters are extracted as if dml is calculating
using pipes as we pass them in. in reality, dml internally merges
pipes into planes if pipe split is detected.

This change adds reverse logic to dcn20_calculate_dlg_params so
that the global sync parameters can be correctly extracted for
all the pipes when pipe split is enabled.
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -234,7 +234,6 @@ struct stream_resource {
 	struct output_pixel_processor *opp;
 #ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
 	struct display_stream_compressor *dsc;
-	int dscclk_khz;
 #endif
 	struct timing_generator *tg;
 	struct stream_encoder *stream_enc;