[bugfix] fix deepseek rope sincoscache re-generation (#2744)

### What this PR does / why we need it?
The current implementation will result in duplicate generation of
`sin_cos_cache` in rope when `kv_seqlen` > 4k, because the
initialization length of the `sin_cos_cache` is only 4k.

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

### How was this patch tested?
After this PR merged, sin_cos_cache will not increase in forward func,
so `test_native_rope_deepseek_forward_cache_handling` is not necessary.

- vLLM version: v0.10.1.1
- vLLM main:
60f0843ef8

Signed-off-by: zzzzwwjj <1183291235@qq.com>

vllm_ascend/torchair/torchair_mla.py

@@ -1198,9 +1198,7 @@ class AscendMLATorchairImpl(MLAAttentionImpl):
             else:
                 decode_q_pe[...], decode_k_pe[...] = self.rotary_emb(
                     attn_metadata.decode.input_positions,
-                    decode_q_pe.contiguous(),
-                    decode_k_pe,
-                    max_seq_len=attn_metadata.decode.max_seq_lens)
+                    decode_q_pe.contiguous(), decode_k_pe)
         if has_prefill:
             assert attn_metadata.prefill is not None
             prefill_q = self.q_proj(prefill_hs_or_q_c)[0]\
@@ -1225,9 +1223,7 @@ class AscendMLATorchairImpl(MLAAttentionImpl):
             else:
                 prefill_q_pe[...], prefill_k_pe[...] = self.rotary_emb(
                     attn_metadata.prefill.input_positions,
-                    prefill_q_pe.contiguous(),
-                    prefill_k_pe,
-                    max_seq_len=attn_metadata.prefill.max_seq_lens)
+                    prefill_q_pe.contiguous(), prefill_k_pe)
 
         assert len(
             kv_cache