Merge branch 'exp_quant_grub2'

dnn/autogen.sh

dnn/dump_data.c

dnn/lpcnet_demo.c

dnn/lpcnet_enc.c

dnn/lpcnet_private.h

dnn/nnet.c

dnn/nnet.h

dnn/training_tf2/dataloader.py

dnn/training_tf2/dump_lpcnet.py

dnn/training_tf2/lpcnet.py

dnn/training_tf2/train_lpcnet.py