BUILD: watchdog: condition it to USE_RT
It's needed on Linux to have access to timerfd_*, and on FreeBSD this
lib is needed as well, though not enabled in our default build. We can
see later if it's OK to enable it, for now let's fix the build issues.
diff --git a/src/wdt.c b/src/wdt.c
index 60a5fd4..19d36c3 100644
--- a/src/wdt.c
+++ b/src/wdt.c
@@ -25,7 +25,7 @@
* It relies on timer_create() and timer_settime() which are only available in
* this case.
*/
-#if defined(USE_THREAD) && (_POSIX_TIMERS > 0) && defined(_POSIX_THREAD_CPUTIME)
+#if defined(USE_THREAD) && defined(USE_RT) && (_POSIX_TIMERS > 0) && defined(_POSIX_THREAD_CPUTIME)
/* We'll deliver SIGALRM when we've run out of CPU as it's not intercepted by
* gdb by default.