[libomptarget][flang] Explicitly pass the OpenMP device libraries to tests (#76796)

This pull request is a follow-up of patch:
https://github.com/llvm/llvm-project/pull/68225 and it explicitly
specifies OpenMP device libraries for Fortran OpenMP tests.

GitOrigin-RevId: 0cdaadf15aaa6609f93e3508417b47baa3891996
1 file changed