firmware: imx: scu-irq: Init workqueue before request mbox channel

With mailbox channel requested, there is possibility that interrupts may
come in, so need to make sure the workqueue is initialized before
the queue is scheduled by mailbox rx callback.

Reviewed-by: Frank Li <[e-mail]>
Signed-off-by: Peng Fan <[e-mail]>
Signed-off-by: Shawn Guo <[e-mail]>

drivers/firmware/imx/imx-scu-irq.c

···
 	cl->dev = dev;
 	cl->rx_callback = imx_scu_irq_callback;
 
+	INIT_WORK(&imx_sc_irq_work, imx_scu_irq_work_handler);
+
 	/* SCU general IRQ uses general interrupt channel 3 */
 	ch = mbox_request_channel_byname(cl, "gip3");
 	if (IS_ERR(ch)) {
···
 		dev_err(dev, "failed to request mbox chan gip3, ret %d\n", ret);
 		goto free_cl;
 	}
-
-	INIT_WORK(&imx_sc_irq_work, imx_scu_irq_work_handler);
 
 	if (!of_parse_phandle_with_args(dev->of_node, "mboxes",
 				       "#mbox-cells", 0, &spec)) {