[LLVM][OpenMP] Correct the function signature of `__kmpc_parallel_level`

`__kmpc_parallel_level` used to be a function w/o any argument, but in the new
device runtime, it accepts two. This patch simply corrects it in `OMPKinds.def`.
```
uint16_t __kmpc_parallel_level(IdentTy *Loc, uint32_t);
```

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D141655