[Hardware][Gaudi]add get_name method for HPUAttentionBackend (#10667)

Signed-off-by: Kunshang Ji <kunshang.ji@intel.com>

vllm/attention/backends/hpu_attn.py

@@ -22,6 +22,10 @@ logger = init_logger(__name__)
 
 class HPUAttentionBackend(AttentionBackend):
 
+    @staticmethod
+    def get_name() -> str:
+        return "HPU_ATTN"
+
     @staticmethod
     def get_impl_cls() -> Type["HPUAttentionImpl"]:
         return HPUAttentionImpl