Support HIP

In the hip_dev branch, LightSeq supports CUDA backend and HIP backend（now support training only）. LightSeq transformer has a speedup about 7% comparing with FairsSeq transformer under the HIP backend. LightSeq HIP supports multiple NLP models, such as transformer, bert, gpt, etc. Users need no modification with python training. More information about the LightSeq HIP can be found here https://github.com/bytedance/lightseq/blob/hip_dev/README_HIP.md