flatten & reshape bug (#113)

1 flatten & reshape 之前没有放到 paddle_use_bridges 中，现在放进去；
2 reshape 中 cnmlCreateNdReshapeOpParam dim_num 之前误写成4，应该是 output_dims.size()

lite/kernels/mlu/bridges/paddle_use_bridges.h

@@ -39,6 +39,10 @@ USE_SUBGRAPH_BRIDGE(layout, kMLU);
 USE_SUBGRAPH_BRIDGE(slice, kMLU);
 USE_SUBGRAPH_BRIDGE(squeeze, kMLU);
 USE_SUBGRAPH_BRIDGE(squeeze2, kMLU);
+USE_SUBGRAPH_BRIDGE(flatten, kMLU);
+USE_SUBGRAPH_BRIDGE(flatten2, kMLU);
+USE_SUBGRAPH_BRIDGE(reshape, kMLU);
+USE_SUBGRAPH_BRIDGE(reshape2, kMLU);
 #ifdef LITE_BUILD_EXTRA
 USE_SUBGRAPH_BRIDGE(gather, kMLU);
 USE_SUBGRAPH_BRIDGE(lrn, kMLU)

lite/kernels/mlu/bridges/reshape_op.cc

@@ -67,8 +67,8 @@ int ReshapeConverter(void* ctx, OpLite* op, KernelBase* kernel) {
   int cnml_trans2_input_shape[4];
   CNML_CALL(
       cnmlGetTensorShape(trans2_input->mlu_tensor(), cnml_trans2_input_shape));
-  CNML_CALL(
-      cnmlCreateNdReshapeOpParam(&reshape_param, cnml_trans2_input_shape, 4));
+  CNML_CALL(cnmlCreateNdReshapeOpParam(
+      &reshape_param, cnml_trans2_input_shape, output_dims.size()));
 
   // Use cnmlCreatexxxOpForward to create op.
   CNML_CALL(cnmlCreateReshapeOp(&reshape_op,