[OpenMP] Fix linker error when building info tool

Summary:
The changes made in D123177 added new targets to the
`LIBOMPTARGET_TESTED_PLUGINS` variable which was linked against when
building the `llvm-omp-target-info` tool. This caused linker errors on
the export scripts. This patch removes that dependency, it still builds
and runs as expected so I will assume it's correct.