Revert "[Feat] Shared expert dp for deepseek and deepseek_mtp (#3495)" (#3586)

### What this PR does / why we need it?
This reverts commit
bf87606932.
### Does this PR introduce _any_ user-facing change?
No.
### How was this patch tested?
E2E vllm serving with `enable_shared_expert_dp: true` in eager mode as
before.


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

Signed-off-by: linfeng-yuan <1102311262@qq.com>

vllm_ascend/models/layers/mla.py

@@ -144,17 +144,8 @@ class AscendMultiHeadLatentAttention(MultiHeadLatentAttentionWrapper):
             hidden_states: torch.Tensor,
             kv_cache: Optional[torch.Tensor] = None,
             attn_metadata: Optional[AttentionMetadata] = None) -> torch.Tensor:
-        forward_context = get_forward_context()
-        sp_enabled = forward_context.sp_enabled
-        need_gather_q_kv = False
-        if sp_enabled and self.debug_layer_idx < self.layers:
-            need_gather_q_kv = True
-        if not sp_enabled or self.debug_layer_idx < self.layers:
-            output_shape = hidden_states.shape
-        else:
-            # used in deepseek mtp layer
-            output_shape = torch.chunk(hidden_states, self.tp_size,
-                                       dim=0)[0].shape
+        need_gather_q_kv = get_forward_context().sp_enabled
+        output_shape = hidden_states.shape
         # FIXME: This does not seem right, should make sure the buffer is fixed
         output = torch.empty(output_shape,
                              dtype=hidden_states.dtype,