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

The SG2044 implement a standard T-HEAD C900 PLIC, which is
already supported by the kernel.

Add compatible string for Sophgo SG2044 plic.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20250413223507.46480-5-inochiama@gmail.com


Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Chen Wang <wangchen20@iscas.ac.cn>