Revert "perf(ROCm): optimize chunked CE loss num_warps for RDNA GPUs (#4123)" (#4139)

This reverts commit 721bf4852a.

unsloth/kernels/cross_entropy_loss.py

@@ -22,7 +22,6 @@ from .utils import (
     triton_cast,
     torch_gpu_device,
     is_cdna,
-    is_rdna,
 )
 from transformers.models.llama.modeling_llama import logger
 from unsloth_zoo.utils import Version
@@ -365,7 +364,7 @@ class Fast_CrossEntropyLoss(torch.autograd.Function):
                     SOFTCAP = logit_softcapping,
                     DO_LOGIT_SCALING = DO_LOGIT_SCALING,
                     LOGIT_SCALE = logit_scaling,
-                    num_warps = 16 if is_cdna() or is_rdna() else 32,
+                    num_warps = 32 if not is_cdna() else 16,
                 )
             # logsumexp(chunked_logsumexp) - x
             # Do the -x separately