net: designware: Add SoCFPGA GMAC DT compatible string

Add the OF compatible property to match the SoCFPGA GMAC.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

drivers/net/designware.c

@@ -608,6 +608,7 @@ static int designware_eth_ofdata_to_platdata(struct udevice *dev)
 
 static const struct udevice_id designware_eth_ids[] = {
 	{ .compatible = "allwinner,sun7i-a20-gmac" },
+	{ .compatible = "altr,socfpga-stmmac" },
 	{ }
 };