dts: intel_ish: Improve and extend ISH dts files

- Add uart1 and uart2 nodes to intel_ish5.dtsi with all required
properties.
- Consistently place properties for all nodes.
- Add #interrupt-cells to the soc node.
- Update intel_ish5_8.dtsi: overrides interrupt and status for
uart1, uart2, and dma0.

These changes add missing peripherals, unify property layout, and
improve clarity for Intel ISH platforms.

Signed-off-by: Dong Wang <dong.d.wang@intel.com>