Defines starting with `s' in bsd/ppc

• SEGOFSET bsd/ppc/param.h:45
• SEGSHIFT bsd/ppc/param.h:46
• SP bsd/ppc/reg.h:32
• STACK_GROWTH_UP bsd/ppc/param.h:53
• STACKSIZE bsd/ppc/param.h:58
• SV_SAVE_REGS bsd/ppc/signal.h:53