Back out previous commit. The description didn't match the commit,

and marking this interrupt as fast isn't quite right.  It also needs
to be MP Safe, and I've not done that work (yet).

sys/dev/ppbus/pps.c

@@ -204,7 +204,7 @@ ppsopen(struct cdev *dev, int flags, int fmt, struct thread *td)
 
 		/* attach the interrupt handler */
 		if ((error = BUS_SETUP_INTR(ppbus, ppsdev, sc->intr_resource,
-			       INTR_TYPE_TTY | INTR_FAST, ppsintr, ppsdev,
+			       INTR_TYPE_TTY, ppsintr, ppsdev,
 			       &sc->intr_cookie))) {
 			ppb_release_bus(ppbus, ppsdev);
 			return (error);