John Baldwin 618f2b4d55 Work around problems with the ppbus(4)'s interesting way of managing
interrupt handlers for child devices by adding a dummy handler that is
always present so that the underlying interrupt thread is always around
avoiding panics from stray interrupts.

MFC after:	3 days
2008-01-10 23:43:47 +00:00
..
2007-02-23 19:34:52 +00:00