tests: ztest: no smp support in unit tests

SMP support for ztest does not apply to unit tests.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

subsys/testsuite/ztest/src/ztest.c

@@ -55,6 +55,7 @@ static int cleanup_test(struct unit_test *test)
 	return ret;
 }
 
+#ifdef KERNEL
 #ifdef CONFIG_SMP
 #define NUM_CPUHOLD (CONFIG_MP_NUM_CPUS - 1)
 #else
@@ -124,6 +125,8 @@ void z_test_1cpu_stop(void)
 	}
 }
 
+#endif
+
 static void run_test_functions(struct unit_test *test)
 {
 	phase = TEST_PHASE_SETUP;