[clang] [llvm] [OpenMP] Remove 'libomptarget.devicertl.a' fatbinary and use static library (PR #126143)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> We already have a host-side `libomptarget`:
> 
> https://github.com/llvm/llvm-project/blob/cfd8980fe79872feb9ed81959aa018681c7b3354/offload/src/CMakeLists.txt#L9

We can have conflicting names since they're in separate install directories. I'd like this to have a more 'standard' name if possible, and I feel putting a `gpu` or something on it is redundant since it's already in the GPU's library dir.

https://github.com/llvm/llvm-project/pull/126143