[libomptarget][amdgpu] Build openmp for two more targets

[libomptarget][amdgpu] Build openmp for two more targets

The 4800U APU is a gfx902 and the MI100 accelerator is a gfx908.
Both numbers are listed in ROCT topology.c

Reviewed By: jhuber6

Differential Revision: https://reviews.llvm.org/D104922