Fix dpr<>bart config for RAG (#8808)

* correct dpr test and bert pos fault

* fix dpr bert config problem

* fix layoutlm

* add config to dpr as well

src/transformers/models/roberta/modeling_roberta.py

@@ -83,7 +83,7 @@ class RobertaEmbeddings(nn.Module):
 
         # position_ids (1, len position emb) is contiguous in memory and exported when serialized
         self.register_buffer("position_ids", torch.arange(config.max_position_embeddings).expand((1, -1)))
-        self.position_embedding_type = config.position_embedding_type
+        self.position_embedding_type = getattr(config, "position_embedding_type", "absolute")
 
         # End copy
         self.padding_idx = config.pad_token_id
@@ -162,7 +162,7 @@ class RobertaSelfAttention(nn.Module):
         self.value = nn.Linear(config.hidden_size, self.all_head_size)
 
         self.dropout = nn.Dropout(config.attention_probs_dropout_prob)
-        self.position_embedding_type = config.position_embedding_type
+        self.position_embedding_type = getattr(config, "position_embedding_type", "absolute")
         if self.position_embedding_type == "relative_key" or self.position_embedding_type == "relative_key_query":
             self.max_position_embeddings = config.max_position_embeddings
             self.distance_embedding = nn.Embedding(2 * config.max_position_embeddings - 1, self.attention_head_size)