We save interrupted TCB state on tcb->xcp.regs not interrupt stack now
which allows us to remove x86_64_savestate() from up_switch_context()
and other places.
Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
Signed-off-by: hujun5 <hujun5@xiaomi.com>