HParams for training languagemodel_lm1b32k_packed.  880M Params.

def lmx_h3k_f12k():
  """HParams for training languagemodel_lm1b32k_packed.  880M Params."""
  hparams = lmx_base()
  hparams.hidden_size = 3072
  hparams.filter_size = 12288
  hparams.batch_size = 2048
  hparams.weight_dtype = "bfloat16"
  return hparams