drm/amd/display: Fix phy id mapping issue for secure display

[Why]
Under mst scenario, mst streams are from the same link_enc_hw_inst.
As the result, can't utilize that as the phy index for distinguising
different stream sinks.

[How]
Sort the connectors by:
link_enc_hw_instance->mst tree depth->mst RAD

After sorting the phy index assignment, store connector's relevant info
into dm mapping array. Once need the index, just look up the static
array.

Reviewed-by: HaoPing Liu <haoping.liu@amd.com>
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -547,6 +547,10 @@ struct amdgpu_display_manager {
 	 * all crtcs.
 	 */
 	struct secure_display_context *secure_display_ctxs;
+
+	bool secure_display_phy_mapping_updated;
+	int phy_id_mapping_cnt;
+	struct phy_id_mapping phy_id_mapping[AMDGPU_DM_MAX_CRTC];
 #endif
 	/**
 	 * @hpd_rx_offload_wq: