Make weights blob a void*

dnn/dred_encoder.c

dnn/dred_encoder.h

dnn/fargan.c

dnn/fargan.h

dnn/lossgen.c

dnn/lossgen.h

dnn/lpcnet.h

dnn/lpcnet_demo.c

dnn/lpcnet_enc.c

dnn/lpcnet_plc.c

dnn/nnet.h

dnn/osce.c

dnn/osce.h

dnn/parse_lpcnet_weights.c

dnn/pitchdnn.c

dnn/pitchdnn.h

include/opus_defines.h

src/opus_demo.c