fix codec/asr/mos model loading for validation
for using MOS model, a container with torchaudio should be used. otherwise, comment MOS model loading and inference 
# What does this PR do ?

When using tensor parallelism, model assumes Nemo codec/ASR/MOS checkpoints are parallelized. This PR will fix loading checkpoints when tp is enabled 

## Who can review?

@zhehuaichen 

