net: ravb: Simplify max-speed handling in ravb_of_to_plat

We can call dev_read_u32_default() instead of calling fdt_getprop() then
fdt32_to_cpu().

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/drivers/net/ravb.c b/drivers/net/ravb.c
index f1401d2..231764e 100644
--- a/drivers/net/ravb.c
+++ b/drivers/net/ravb.c
@@ -649,7 +649,6 @@
 int ravb_of_to_plat(struct udevice *dev)
 {
 	struct eth_pdata *pdata = dev_get_plat(dev);
-	const fdt32_t *cell;
 
 	pdata->iobase = dev_read_addr(dev);
 
@@ -657,10 +656,7 @@
 	if (pdata->phy_interface == PHY_INTERFACE_MODE_NA)
 		return -EINVAL;
 
-	pdata->max_speed = 1000;
-	cell = fdt_getprop(gd->fdt_blob, dev_of_offset(dev), "max-speed", NULL);
-	if (cell)
-		pdata->max_speed = fdt32_to_cpu(*cell);
+	pdata->max_speed = dev_read_u32_default(dev, "max-speed", 1000);
 
 	sprintf(bb_miiphy_buses[0].name, dev->name);