[llvm] [OFFLOAD] Add plugin with support for Intel oneAPI Level Zero (PR #158900)

[Alexey Sachkov via llvm-commits]

================
@@ -0,0 +1,69 @@
+if(NOT LIBOMPTARGET_DEP_LEVEL_ZERO_FOUND)
+return()
----------------
AlexeySachkov wrote:

```suggestion
  return()
```

https://github.com/llvm/llvm-project/pull/158900