soc: ti: wkup_m3_ipc: Use dev_err_probe

During probe the mailbox channel might not yet be available. Use
dev_err_probe to silence this deferred probe error message:
wkup_m3_ipc 44e11324.wkup_m3_ipc: IPC Request for A8->M3 Channel failed! -517

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20250509093652.1866566-1-alexander.stein@ew.tq-group.com
Signed-off-by: Nishanth Menon <nm@ti.com>

Author: tq-steina

drivers/soc/ti/wkup_m3_ipc.c

@@ -644,11 +644,9 @@ static int wkup_m3_ipc_probe(struct platform_device *pdev)
 
 	m3_ipc->mbox = mbox_request_channel(&m3_ipc->mbox_client, 0);
 
-	if (IS_ERR(m3_ipc->mbox)) {
-		dev_err(dev, "IPC Request for A8->M3 Channel failed! %ld\n",
-			PTR_ERR(m3_ipc->mbox));
-		return PTR_ERR(m3_ipc->mbox);
-	}
+	if (IS_ERR(m3_ipc->mbox))
+		return dev_err_probe(dev, PTR_ERR(m3_ipc->mbox),
+				     "IPC Request for A8->M3 Channel failed!\n");
 
 	if (of_property_read_u32(dev->of_node, "ti,rproc", &rproc_phandle)) {
 		dev_err(&pdev->dev, "could not get rproc phandle\n");