arch: arc: adjust privileged stack size of arc to 384 bytes
arch: arc: adjust privileged stack size of arc to 384 bytes

Considering the case of call of printk, interrupt and
other cases, adjust the privileged stack size of arc to
384 bytes to avoid the the overflow of privileged stack.

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

zephyriot/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,kraj/zephyr,ldts/zephyr,kraj/zephyr,Vudentz/zephyr,galak/zephyr,mbolivar/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,zephyriot/zephyr,nashif/zephyr,Vudentz/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,punitvara/zephyr,mbolivar/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,punitvara/zephyr,punitvara/zephyr,galak/zephyr,ldts/zephyr,nashif/zephyr,kraj/zephyr,Vudentz/zephyr,zephyriot/zephyr,Vudentz/zephyr,zephyriot/zephyr,finikorg/zephyr,Vudentz/zephyr,kraj/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,explora26/zephyr,punitvara/zephyr,nashif/zephyr,kraj/zephyr,mbolivar/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,mbolivar/zephyr,galak/zephyr,Vudentz/zephyr,explora26/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,mbolivar/zephyr