Use setting from devicetree to drive the default setting for
CORTEX_M_SYSTICK. We update the dts files to default systick to be
enabled since the major of cortex-m platforms utilize it by default
(except on Nordic SoCs, TI CC13x2/CC26x2 and MEC1501 in which we
default to disabled).
Fixes#25299
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
