Convert device tree binding fsl,ls-scfg-msi to yaml format.

Additional changes:
- Include gic.h and use predefined macro in example.
- Remove label in example.
- Change node name to interrupt-controller in example.
- Fix error in example.
- ls1046a allow 4 irqs, other platform only 1 irq.
- Add $ref: msi-controller.yaml
- Add #msi-cells.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240627144207.4003708-1-Frank.Li@nxp.comSigned-off-by: Rob Herring (Arm) <robh@kernel.org>