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 <[e-mail]>
Reviewed-by: Alexandre Belloni <[e-mail]>
Acked-by: Nicolas Ferre <[e-mail]>
Acked-by: Mark Rutland <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/base/power/wakeup.c

···
 	pm_abort_suspend = true;
 	freeze_wake();
 }
+EXPORT_SYMBOL_GPL(pm_system_wakeup);
 
 void pm_wakeup_clear(void)
 {