dt-bindings: net: dsa: mediatek,mt7530: update examples

Update the examples on the binding.

- Add examples which include a wide variation of configurations.
- Make example comments YAML comment instead of DT binding comment.
- Add interrupt controller to the examples. Include header file for
interrupt.
- Change reset line for MT7621 examples.
- Pretty formatting for the examples.
- Change switch reg to 0.
- Change port labels to fit the example, change port 4 label to wan.

Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>