Added #include of <sys/queue.h> to make this self-sufficient.

Includers of this file apparently didn't know that <sys/queue.h>
was a prerequisite and include a semi-random collection headers
until one happened to include it.

sys/dev/ppbus/ppbconf.h

@@ -23,12 +23,14 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: ppbconf.h,v 1.1 1997/08/14 13:57:42 msmith Exp $
+ *	$Id: ppbconf.h,v 1.2 1997/08/16 14:05:36 msmith Exp $
  *
  */
 #ifndef __PPBCONF_H
 #define __PPBCONF_H
 
+#include <sys/queue.h>
+
 /*
  * Parallel Port Bus sleep/wakeup queue.
  */