[Misc] Clean up uesless code in attention (#1933)

Before do attention module refactor, we can do some code cleanup to make
the next step easier.

What this PR does:

1. remove uesless `common_prefix_len` for attention builder
2. remove uesless `is_only_prefill` and `num_input_tokens` in attention
metadata.
3. remove `CommonAttentionMetadata` and ues `query_start_loc` instead,
`CommonAttentionMetadata` is over designed and uesless
4. update the attention backend input parameters to keep the same as
vLLM.
5. Rename attention name to the same style with `ASCEND` prefix

- vLLM version: v0.9.2
- vLLM main:
107111a859

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

vllm_ascend/worker/mtp_proposer_v1.py

@@ -8,7 +8,6 @@ from vllm.model_executor.model_loader.utils import (
     process_weights_after_loading, set_default_torch_dtype)
 from vllm.v1.sample.metadata import SamplingMetadata
 
-from vllm_ascend.attention.mla_v1 import CommonAttentionMetadata
 from vllm_ascend.models.deepseek_mtp import CustomDeepSeekMTP
 
 
@@ -100,11 +99,6 @@ class MtpProposer:
         query_lens = cu_num_tokens[1:] - cu_num_tokens[:-1]
         max_query_len = query_lens.max().item()
 
-        seq_lens = (target_positions[last_token_indices] + 1)
-
-        common_attn_metadata = CommonAttentionMetadata(
-            query_start_loc=cu_num_tokens, seq_lens=seq_lens)
-
         # FIXME: reorder_batch() needs to be called before build()
         # because fields of attn_metadata_builder needs to be updated.
         # However, currently reorder_batch() takes input_batch and
@@ -120,8 +114,7 @@ class MtpProposer:
             num_reqs=batch_size,
             num_actual_tokens=num_tokens,
             max_query_len=max_query_len,
-            common_prefix_len=0,
-            common_attn_metadata=common_attn_metadata,
+            query_start_loc=cu_num_tokens,
         )
 
         with set_forward_context(attn_metadata, self.vllm_config):