mailbox: rockchip: add irq wake up support

Parse and enable irq wakeup if the "wakeup-source" property was present.

Change-Id: I21b974d65dc02c1f3bd5f0e52a1372367b77a6e4
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>

drivers/mailbox/rockchip-mailbox.c

@@ -224,6 +224,9 @@ static int rockchip_mbox_probe(struct platform_device *pdev)
 							mb);
 			if (ret < 0)
 				return ret;
+
+			if (device_property_present(&pdev->dev, "wakeup-source"))
+				enable_irq_wake(irq);
 		}
 
 		mb->chans[i].idx = i;