PM: sleep: wakeirq: drop useless parameter from dev_pm_attach_wake_irq()

This function has the 'irq' parameter which isn't ever used, so drop it.

Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>