boards: stm32: Turn hardware stack protection on by default

Enable HW stack protection by default on all STM32 when possible.
This excludes all series based on M0(FO) and M0+(G0/L0).
Also this is made only on boards with enabled MPU (SRAM > 64K).

Cf similar change on nRF boards: #28470

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>