DeepSpeed

54930203 - Use accelerator API for dtype selection in Newton-Schulz iterations

Use accelerator API for dtype selection in Newton-Schulz iterations Both NS functions now query the accelerator to choose compute dtype instead of hardcoding. Standard NS uses is_bf16_supported() to select bf16 vs fp32; Gram NS uses is_fp16_supported() to select fp16 vs fp32. Signed-off-by: Ma, Guokai <guokai.ma@gmail.com>