Fix FlaxBigBirdEmbeddings (#17842)

Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

src/transformers/models/big_bird/modeling_flax_big_bird.py

@@ -229,8 +229,8 @@ class FlaxBigBirdEmbeddings(nn.Module):
         hidden_states = inputs_embeds + token_type_embeddings + position_embeds
 
         # Layer Norm
-        hidden_states = self.LayerNorm(hidden_states)
         hidden_states = self.dropout(hidden_states, deterministic=deterministic)
+        hidden_states = self.LayerNorm(hidden_states)
         return hidden_states