Documentation: devres: update IRQ helper

devm_irq_sim_init() has been changed to devm_irq_domain_create_sim()
in commit 337cbeb2

 ("genirq/irq_sim: Simplify the API").

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220927083819.12484-1-yangyingliang@huawei.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>