genirq: fix kerneldoc comment for irq_desc

commit 0c6f8a8b

 ("genirq: Remove compat code") deleted the @status
member of irq_desc, but forgot to update the comment.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>