[MLU] fix celoss to use valid_label. (#45201)

python/paddle/nn/functional/loss.py

@@ -2299,6 +2299,12 @@ def cross_entropy(input,
                 raise ValueError("Target {} is out of upper bound.".format(
                     label_max.item()))
         if core.is_compiled_with_npu() or core.is_compiled_with_mlu():
+            if soft_label == False:
+                _, _, out = _C_ops.softmax_with_cross_entropy(
+                    input, valid_label, 'soft_label', soft_label,
+                    'ignore_index', ignore_index, 'numeric_stable_mode', True,
+                    'axis', axis, 'use_softmax', use_softmax)
+            else:
                 _, _, out = _C_ops.softmax_with_cross_entropy(
                     input, label, 'soft_label', soft_label, 'ignore_index',
                     ignore_index, 'numeric_stable_mode', True, 'axis', axis,