[clang] Pass --cuda-path to fix test/Driver/openmp-offload-jit.c

This test was trying to detect a system installation of CUDA and was
marked as returning exit code 1 as part of D156363. Pass an explicit
CUDA installation to make the test return exit code 0 regardless of
a CUDA being found on the system or not. Also add an explicit -march
to get a stable test.