net: keystone_net: move serdes setup to initialization function

On Keystone2 devices serdes must be initialized before accessing MDIO bus.
This commit moves the keystone2_net_serdes_setup() from keystone2_eth_open
to keystone2_emac_initialize to meet that requirement.

This also eliminates unnecessary serdes initializatin every time when the
keystone2_eth_open is being called.

Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Tested-by: Nishanth Menon <nm@ti.com>

drivers/net/keystone_net.c

@@ -398,8 +398,6 @@ static int keystone2_eth_open(struct eth_device *dev, bd_t *bis)
 	sys_has_mdio =
 		(eth_priv->sgmii_link_type == SGMII_LINK_MAC_PHY) ? 1 : 0;
 
-	keystone2_net_serdes_setup();
-
 	if (sys_has_mdio)
 		keystone2_mdio_reset(mdio_bus);
 
@@ -556,6 +554,8 @@ int keystone2_emac_initialize(struct eth_priv_t *eth_priv)
 			return res;
 	}
 
+	keystone2_net_serdes_setup();
+
 	/* Create phy device and bind it with driver */
 #ifdef CONFIG_KSNET_MDIO_PHY_CONFIG_ENABLE
 	phy_dev = phy_connect(mdio_bus, eth_priv->phy_addr,