[KVPool]Fix PP get bug (#5007)

### What this PR does / why we need it?

When kv caches are evicted from the key-value pool, it's possible that
the kv cache for pp0 is still active, but the kv cache for pp1 has
already been evicted. Therefore, a unified check is needed during the
get operation.


- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

Signed-off-by: baxingpiaochong <771405853@qq.com>
Co-authored-by: Jade Zheng <zheng.shoujian@outlook.com>

vllm_ascend/distributed/kvpool/pool_worker.py

@@ -572,7 +572,8 @@ class KVPoolWorker:
                 num_block = len(keys) // self.num_layers
             multi_tp_values = [
                 res[i * num_block:(i + 1) * num_block]  # type: ignore[index]
-                for i in range(min(self.tp_size, self.num_kv_head))
+                for i in range(
+                    min(self.tp_size, self.num_kv_head) * self.pp_size)
             ]
             index = self.find_min_first_non_one_index(multi_tp_values)
             if index != -1: