Defines starting with `n' in bsd/ppc

• NBPG bsd/ppc/param.h:43
• NBSEG bsd/ppc/param.h:47
• NIOPIDS bsd/ppc/param.h:147
• NMAGIC bsd/ppc/exec.h:81
• NMBCLUSTERS bsd/ppc/param.h:78
• NPIDS bsd/ppc/param.h:146