arch: arm: aarch32: add z_arm_reserved only when we have SysTick
arch: arm: aarch32: add z_arm_reserved only when we have SysTick

If the Cortex-M core does not implement the SysTick peripheral,
we should not be adding z_arm_reserved in the corresponding
vector table entry. If we do have SysTick implemented but we
are not using it as the system timer, we shall install the
reserved interrupt at the vector table entry.

Signed-off-by: Ioannis Glaropoulos <5921cc8bab7e1d4329f52fd8f6268f9692e3de80@nordicsemi.no>

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