[feature] chunkprefill support pcp&dcp (#3801)

### What this PR does / why we need it?
ChunkPrefill now can support Long Sequence Feature Pcp&Dcp

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
CI tests passed with self-test


- vLLM version: v0.11.0
- vLLM main:
83f478bb19

---------

Signed-off-by: Apocalypse990923-qshi <qiushixu@usc.edu>
Signed-off-by: Delphine-Nic <tanwenqin@huawei.com>
Co-authored-by: Delphine-Nic <tanwenqin@huawei.com>
Co-authored-by: Delphine-Nic <3834144971@qq.com>

tests/ut/attention/test_attention_v1.py

@@ -83,6 +83,7 @@ class TestAscendAttentionMetadataBuilder(TestBase):
         self.mock_vllm_config.compilation_config.cudagraph_mode = None
         self.mock_vllm_config.scheduler_config.max_num_seqs = 10
         self.mock_vllm_config.scheduler_config.decode_max_num_seqs = 10
+        self.mock_vllm_config.scheduler_config.chunked_prefill_enabled = False
         self.mock_device = 'cpu:0'
         self.builder = AscendAttentionMetadataBuilder(None, None,
                                                       self.mock_vllm_config,