Merge pull request #910 from kuke/aishell_profile

Add profile in aishell example

fluid/DeepASR/examples/aishell/profile.sh

+export CUDA_VISIBLE_DEVICES=2,3,4,5
+python -u ../../tools/profile.py --feature_lst data/train_feature.lst \
+                   --label_lst data/train_label.lst \
+                   --mean_var data/aishell/global_mean_var \
+                   --parallel \
+                   --frame_dim 2640  \
+                   --class_num 101  \