net: phy: smsc: LAN8710/20: add PHY_RST_AFTER_CLK_EN flag

The Microchip/SMSC LAN8710/LAN8720 PHYs need (according to their
datasheet [1]) a continuous REF_CLK when configured to "REF_CLK In Mode".
Therefore set the PHY_RST_AFTER_CLK_EN flag for those PHYs to let the
ETH driver reset them after the REF_CLK is enabled.

[1] http://ww1.microchip.com/downloads/en/DeviceDoc/00002165B.pdf

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/smsc.c

@@ -312,7 +312,7 @@ static struct phy_driver smsc_phy_driver[] = {
 	.name		= "SMSC LAN8710/LAN8720",
 
 	.features	= PHY_BASIC_FEATURES,
-	.flags		= PHY_HAS_INTERRUPT,
+	.flags		= PHY_HAS_INTERRUPT | PHY_RST_AFTER_CLK_EN,
 
 	.probe		= smsc_phy_probe,