Defines starting with `n' in machdep/ppc

• NARGS machdep/ppc/frame.h:95
• NBITS machdep/ppc/unix_signal.c:52
• NBSEG machdep/ppc/fault_copy.c:56
• NCONSOPS machdep/ppc/serial_console.c:116
• NDRIVERS machdep/ppc/kernBootStruct.h:43
• NSCC machdep/ppc/serial_io.c:33
• NSCC_LINE machdep/ppc/scc_8530.h:372
• NULL machdep/ppc/DeviceTree.c:32
• NUMARGREGS machdep/ppc/frame.h:157