[llvm] [libsycl] Add Maintainers.rst file (PR #168550)

[Tom Honermann via llvm-commits]

================
@@ -0,0 +1,16 @@
+=====================
+libsycl Maintainers
+=====================
+
+This file is a list of the
+`maintainers <https://llvm.org/docs/DeveloperPolicy.html#maintainers>`_ for
+libsycl.
+
+Current Maintainers
+========
----------------
tahonermann wrote:

```suggestion
Current Maintainers
===================
```

https://github.com/llvm/llvm-project/pull/168550