ASoC: loongson: change the type of variable irq to int

We use variable 'irq' to store the return value of fwnode_get_irq_byname().
A negative value indicates that the operation failed. If the type of 'irq'
is unsigned int, we never know if the operation failed.

Reported-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Closes: https://lore.kernel.org/loongarch/325dd825-6fa5-0ebc-4b7e-7acf2d2840e4@loongson.cn/


Signed-off-by: YingKun Meng <mengyingkun@loongson.cn>
Link: https://lore.kernel.org/r/20230619074649.3608726-1-mengyingkun@loongson.cn


Signed-off-by: Mark Brown <broonie@kernel.org>