tests/sys/kern: Skip some timer tests if ncpu == 1

PR:		299223
MFC after:	1 week

(cherry picked from commit 62f54beab0)

tests/sys/kern/timerfd.c

@@ -715,6 +715,9 @@ ATF_TC_HEAD(timerfd__periodic_timer_performance, tc)
 }
 ATF_TC_BODY(timerfd__periodic_timer_performance, tc)
 {
+	if (sysconf(_SC_NPROCESSORS_CONF) < 2)
+		atf_tc_skip("Test livelocks with one CPU, see PR 299223");
+
 	int timerfd = timerfd_create(CLOCK_MONOTONIC, /**/
 	    TFD_CLOEXEC | TFD_NONBLOCK);
 

tests/sys/kqueue/kqueue_fork.c

@@ -281,6 +281,9 @@ ATF_TC_BODY(cponfork_timer_race, tc)
 	int error, kq, status;
 	pid_t pid;
 
+	if (sysconf(_SC_NPROCESSORS_CONF) < 2)
+		atf_tc_skip("Test livelocks with one CPU, see PR 299223");
+
 	for (int i = 0; i < 100; i++) {
 		kq = kqueuex(KQUEUE_CPONFORK);
 		ATF_REQUIRE(kq >= 0);