[Speculative Decoding] Add MTP logprob support for PD disaggregation (#7442)

* support mtp logprob in pd

* fix

* fix

* fix

* fix xpu bugs

custom_ops/gpu_ops/speculate_decoding/speculate_logprob_msg.h

@@ -0,0 +1,39 @@
+// Copyright (c) 2026 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/ipc.h>
+#include <sys/msg.h>
+#include <sys/types.h>
+#include "paddle/extension.h"
+
+#define SPEC_LOGPROB_MAX_BSZ 512
+#define SPEC_LOGPROB_K 20
+#define MAX_DRAFT_TOKEN_NUM 6
+
+struct batch_msgdata {
+  int tokens[MAX_DRAFT_TOKEN_NUM * (SPEC_LOGPROB_K + 1)];
+  float scores[MAX_DRAFT_TOKEN_NUM * (SPEC_LOGPROB_K + 1)];
+  int ranks[MAX_DRAFT_TOKEN_NUM];
+};
+
+struct msgdata {
+  long mtype;
+  // stop_flag, message_flag, bsz, batch_token_nums
+  int meta[3 + SPEC_LOGPROB_MAX_BSZ];
+  batch_msgdata mtext[SPEC_LOGPROB_MAX_BSZ];
+};