add poweroff command

hc

2023-12-14 982b8cc116118b3463d3f332581945625722acd8

 kernel/arch/m68k/hp300/time.h
..
..
@@ -1,2 +1 @@
1
1
 extern void hp300_sched_init(irq_handler_t vector);
2
-extern u32 hp300_gettimeoffset(void);