tests: cmsis_v1: properly set stack size
tests: cmsis_v1: properly set stack size

There are limits to CMSIS stack sizes, we can't just
add a number to it. Use the configured maximum.

Signed-off-by: Andrew Boie <aab045b28152628be6af0e556050d0381fd0a34d@intel.com>

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