dt-bindings: interrupt-controller: Add Sophgo SG2042 MSI

Add binding for Sophgo SG2042 MSI controller.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/all/44de02977624be334ba6328acfdbb2a375f2071f.1740535748.git.unicorn_wang@outlook.com