PM / wakeup: export pm_system_wakeup symbol

PM / wakeup: export pm_system_wakeup symbol

Export pm_system_wakeup function to allow irq handlers to deal with system
wakeup.

This is needed for shared IRQ lines where one of the handler is registered
with IRQF_NO_SUSPEND, while the other ones want to configure it as a wakeup
source.

In this specific case, irq core does not handle the wakeup process and
leave the decision to each irq handler.

Signed-off-by: Boris Brezillon <[email protected]>
Reviewed-by: Alexandre Belloni <[email protected]>
Acked-by: Nicolas Ferre <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>