drm/amd/display: add debugfs sdp hook up function for Navi

[why]
need to send immediate SDP message via debugfs on Navi board.

[how]
hook up the DCN1x encoder function of sending immediate sdp
message to DCN2.
Signed-off-by: David (Dingchen) Zhang <dingchen.zhang@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@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/dcn20/dcn20_stream_encoder.c

@@ -561,6 +561,8 @@ static const struct stream_encoder_funcs dcn20_str_enc_funcs = {
 		enc2_stream_encoder_stop_hdmi_info_packets,
 	.update_dp_info_packets =
 		enc2_stream_encoder_update_dp_info_packets,
+	.send_immediate_sdp_message =
+		enc1_stream_encoder_send_immediate_sdp_message,
 	.stop_dp_info_packets =
 		enc1_stream_encoder_stop_dp_info_packets,
 	.dp_blank =