soc: nxp: kinetis: ke1xz: add support cpu power states

Enable the NXP Kinetis Low Power Timer (LPTMR) timer driver when
power management is enabled.
When the NXP KE1xZ SoC series is using the Arm SysTick as hardware
timer, the cycles/second will always be equal to the CPU core clock
frequency.

Signed-off-by: Anke Xiao <anke.xiao@nxp.com>
4 files changed