macb: Update compatibility string for SiFive FU540-C000

Update the compatibility string for SiFive FU540-C000 as per the new
string updated in the binding doc.
Reference:
https://lore.kernel.org/netdev/CAJ2_jOFEVZQat0Yprg4hem4jRrqkB72FKSeQj4p8P5KA-+rgww@mail.gmail.com/Signed-off-by: Yash Shah <yash.shah@sifive.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com>
Tested-by: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cadence/macb_main.c

@@ -4154,7 +4154,7 @@ static const struct of_device_id macb_dt_ids[] = {
 	{ .compatible = "cdns,emac", .data = &emac_config },
 	{ .compatible = "cdns,zynqmp-gem", .data = &zynqmp_config},
 	{ .compatible = "cdns,zynq-gem", .data = &zynq_config },
-	{ .compatible = "sifive,fu540-macb", .data = &fu540_c000_config },
+	{ .compatible = "sifive,fu540-c000-gem", .data = &fu540_c000_config },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, macb_dt_ids);