[mlir] #include CRunnerUtils.h instead of RunnerUtils.h in SPIRV-runner

This avoids bazel builds failing after commit bba2b656 because libmlir_test_spirv_cpu_runner_c_wrappers.so registers the same runner functions twice.

More precisely, this problem only shows up internally at Google because the bazel build does not have that target.

Either way though, it's better to IWYU.