dt-bindings: interrupt-controller: Add Sophgo SG2044 MSI controller

Like SG2042, SG2044 also uses an external MSI controller to provide
MSI interrupt for PCIe controllers. The difference between these
two MSI controllers are:

  1. SG2044 acks the interrupt by writing 0, SG2042 by setting the
     bit related to the interrupt.

  2. SG2044 uses interrupt number modulo 32 as MSI message data, but
     SG2042 uses the bit related to the interrupt.

Add support for the SG2044 MSI controller.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Chen Wang <wangchen20@iscas.ac.cn> # SG2042
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/all/20250413224922.69719-2-inochiama@gmail.com