spi: cadence: Change cs property reading.

In current implementation cs property can be read only from
device-tree(for_each_available_child_of_node_scoped). Change it to fwnode
based read to allow property reading in ACPI case too.
Signed-off-by: Witold Sadowski <wsadowski@marvell.com>
Signed-off-by: Piyush Malgujar <pmalgujar@marvell.com>
Link: https://patch.msgid.link/20240724154739.582367-9-wsadowski@marvell.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-cadence-xspi.c

@@ -837,15 +837,20 @@ static irqreturn_t cdns_xspi_irq_handler(int this_irq, void *dev)
 
 static int cdns_xspi_of_get_plat_data(struct platform_device *pdev)
 {
-	struct device_node *node_prop = pdev->dev.of_node;
+	struct fwnode_handle *fwnode_child;
 	unsigned int cs;
 
-	for_each_available_child_of_node_scoped(node_prop, node_child) {
-		if (of_property_read_u32(node_child, "reg", &cs)) {
+	device_for_each_child_node(&pdev->dev, fwnode_child) {
+		if (!fwnode_device_is_available(fwnode_child))
+			continue;
+
+		if (fwnode_property_read_u32(fwnode_child, "reg", &cs)) {
 			dev_err(&pdev->dev, "Couldn't get memory chip select\n");
+			fwnode_handle_put(fwnode_child);
 			return -ENXIO;
 		} else if (cs >= CDNS_XSPI_MAX_BANKS) {
 			dev_err(&pdev->dev, "reg (cs) parameter value too large\n");
+			fwnode_handle_put(fwnode_child);
 			return -ENXIO;
 		}
 	}