net: ethernet: stmmac: dwmac-sun8i: enable support of unicast filtering

When adding more MAC addresses to a dwmac-sun8i interface, the device goes
directly in promiscuous mode.
This is due to IFF_UNICAST_FLT missing flag.

So since the hardware support unicast filtering, let's add IFF_UNICAST_FLT.

Fixes: 9f93ac8d ("net-next: stmmac: Add dwmac-sun8i")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/dwmac-sun8i.c

@@ -1015,6 +1015,8 @@ static struct mac_device_info *sun8i_dwmac_setup(void *ppriv)
 	mac->mac = &sun8i_dwmac_ops;
 	mac->dma = &sun8i_dwmac_dma_ops;
 
+	priv->dev->priv_flags |= IFF_UNICAST_FLT;
+
 	/* The loopback bit seems to be re-set when link change
 	 * Simply mask it each time
 	 * Speed 10/100/1000 are set in BIT(2)/BIT(3)