firmware: scmi: mailbox transport: use plat data, not priv data

Change SCMI mailbox transport drivers to use platform data rather
than private data for channel reference since it only stores platform
data retrieved from the DT. Consequently the probe handler is replaced
with a of_to_plat handler.

Cc: Simon Glass <sjg@chromium.org>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/drivers/firmware/scmi/mailbox_agent.c b/drivers/firmware/scmi/mailbox_agent.c
index eb841d6..8e4af0c 100644
--- a/drivers/firmware/scmi/mailbox_agent.c
+++ b/drivers/firmware/scmi/mailbox_agent.c
@@ -33,7 +33,7 @@
 
 static int scmi_mbox_process_msg(struct udevice *dev, struct scmi_msg *msg)
 {
-	struct scmi_mbox_channel *chan = dev_get_priv(dev);
+	struct scmi_mbox_channel *chan = dev_get_plat(dev);
 	int ret;
 
 	ret = scmi_write_msg_to_smt(dev, &chan->smt, msg);
@@ -62,9 +62,9 @@
 	return ret;
 }
 
-int scmi_mbox_probe(struct udevice *dev)
+int scmi_mbox_of_to_plat(struct udevice *dev)
 {
-	struct scmi_mbox_channel *chan = dev_get_priv(dev);
+	struct scmi_mbox_channel *chan = dev_get_plat(dev);
 	int ret;
 
 	chan->timeout_us = TIMEOUT_US_10MS;
@@ -95,7 +95,7 @@
 	.name		= "scmi-over-mailbox",
 	.id		= UCLASS_SCMI_AGENT,
 	.of_match	= scmi_mbox_ids,
-	.priv_auto	= sizeof(struct scmi_mbox_channel),
-	.probe		= scmi_mbox_probe,
+	.plat_auto	= sizeof(struct scmi_mbox_channel),
+	.of_to_plat	= scmi_mbox_of_to_plat,
 	.ops		= &scmi_mbox_ops,
 };