ARC: handle the difference of GNU & MWDT assembly for CONFIG_SMP=y
ARC: handle the difference of GNU & MWDT assembly for CONFIG_SMP=y

Handle the difference of GNU & MWDT assembly for ARC-specific
code guarded by CONFIG_SMP define. That fixies SMP platforms build
with MWDT toolchain.

Signed-off-by: Eugeniy Paltsev <ec089b543c2604b626d7ce60c03e4d074ed102c7@synopsys.com>

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