dt-bindings: interrupt-controller: Add T-HEAD C900 ACLINT SSWI device

Sophgo SG2044 has a new version of T-HEAD C920, which implement a fully
featured T-HEAD ACLINT device. This ACLINT device contains a SSWI device to
support fast S-mode IPI.

Add necessary compatible string for the T-HEAD ACLINT SSWI device.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/all/20241031060859.722258-2-inochiama@gmail.com
Link: https://www.xrvm.com/product/xuantie/C920