kernel: need to release spinlock before busy_wait
kernel: need to release spinlock before busy_wait

need to release spinlock first before busy_wait,
or other cores cannot get the spinlock when the holder is
busy waitting.

Signed-off-by: Wayne Ren <d5c6d7c4aa45e53f819f17870783d153a32ba7d0@synopsys.com>

nashif/zephyr,galak/zephyr,Vudentz/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,finikorg/zephyr,nashif/zephyr,finikorg/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,nashif/zephyr