Fix typo: Correct 'piepling' to 'pipelining' in kernel comments for clarity in software optimization. (#4897)

This PR fixes a typo in the comments of the softmax kernel function,
where "piepling" was mistakenly used instead of "pipelining". The change
ensures that the term accurately reflects the correct meaning of
"pipelining" in software stages.

### Checklist

- [x] I am not making a trivial change, such as fixing a typo in a
comment.
- (Note: While this change fixes a typo, it corrects an important
technical term—'pipelining'—which is crucial for understanding the
kernel's functionality.)
  
- [x] I have written a PR description following these
[rules](https://cbea.ms/git-commit/#why-not-how).

- [x] I have run `pre-commit run --from-ref origin/main --to-ref HEAD`.

- Select one of the following.
  - [ ] I have added tests.
- [x] This PR does not need a test because it only fixes a typo in a
comment.

- Select one of the following.
  - [x] I have not added any `lit` tests.
- [ ] The `lit` tests I have added follow these [best
practices](https://mlir.llvm.org/getting_started/TestingGuide/#filecheck-best-practices),
including the "tests should be minimal" section.

Author: yuWeiCute

python/tutorials/02-fused-softmax.py

@@ -132,7 +132,7 @@ def softmax(x):
     # way so you don't have to come up with manual heuristics yourself.
     num_warps = 8
 
-    # Number of software piepling stages.
+    # Number of software pipelining stages.
     num_stages = 4 if SIZE_SMEM > 200000 else 2
 
     # Allocate output