bsim: test: fix missing warnings in bsim test build system
bsim: test: fix missing warnings in bsim test build system

bsim test build system hides compile warnings.
The problem had been fixed before but due to a regression came again.
This commit adds extra cc flags to prevent this.

Signed-off-by: Aleksandr Khromykh <cef6639e6ba1ae7ad5e7f21adf673d232995fb14@nordicsemi.no>

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