dts: arm: nxp: nxp_ke1xz.dtsi: add lptmr support

Add lptmr support for ke17z, add related configuration for lptmr
driver.
Add supported CPU power states for idle, stop, partial stop 1, and
partial stop 2.

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