lib: utils/ipi: mswi: add separate T-Head C9xx CLINT mswi compatible

Like the mtimer of T-HEAD C9xx clint, the mswi also needs new compatible
string to avoid misuse.

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>
Link: https://lore.kernel.org/linux-riscv/1f6b82a1864477a51db33d3f295889ff985b497b.1696433229.git.unicorn_wang@outlook.com/


Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Anup Patel <anup@brainfault.org>