Defines starting with `n' in kern

• NKSIZE kern/kalloc.c:80
• NO_CHAR kern/miniMonPrivate.h:46
• NO_IPLMEAS kern/xpr.c:38
• NRQS kern/sched.h:91
• NSEC_PER_TICK kern/clock.h:44
• NULL kern/miniMonPrivate.h:48
• NUMQUEUES kern/sched_prim.c:184
• NUM_UDP_HOST_PORTS kern/kdp_protocol.h:74