testsuite: Fix omp-parallel-for-get-min.c and -for-1.c for non-openmp

The recently added tests missed checking for "fopenmp" (see
other tests where "-fopenmp" is passed), which makes them
fail on non-openmp systems.

	* gcc.dg/analyzer/omp-parallel-for-get-min.c,
	gcc.dg/analyzer/omp-parallel-for-1.c: Require effective target fopenmp.