build: add debug configure flag

Signed-off-by: Thynson <lanxingcan@gmail.com>
export spin_init and spin_uninit, user need to manually call them

Signed-off-by: Thynson <lanxingcan@gmail.com>
Add spin_debug

Signed-off-by: Thynson <lanxingcan@gmail.com>
rename spin_poller to spin_global

Signed-off-by: Thynson <lanxingcan@gmail.com>
move misc function to spin.h

Signed-off-by: Thynson <lanxingcan@gmail.com>