[Feat] Shared expert dp for deepseek and deepseek_mtp (#3495)

### What this PR does / why we need it?
shared expert dp for deepseek and deepseek_mtp, could be combined with
sp to improve performance.

### How was this patch tested?

- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

---------

Signed-off-by: zhaozx-cn <zhaozx2116@163.com>
Co-authored-by: realliujiaxu <realliujiaxu@163.com>

vllm_ascend/attention/mla_v1.py

@@ -1245,7 +1245,8 @@ class AscendMLAImpl(MLAAttentionImpl):
             current_ms_metadata = get_multistream_comm_context()
             if current_ms_metadata is not None:
                 with torch.npu.stream(current_ms_metadata.comm_stream):
-                    o_proj_input[num_decode_tokens:] = output_prefill
+                    o_proj_input[
+                        num_decode_tokens:num_actual_tokens] = output_prefill
                     current_ms_metadata.after_comm_event.record()
             else:
                 o_proj_input[