drivers: nxp_enet: Check link state in iface init

Still mark the iface as down after ethernet_init, but then actually
check the link state and initialize carrier appropriately

This fixes the case where, the phy driver doesn't give a callback after
iface init due to the link already being up, there was no change from
the phy driver perspective, so callback  wouldn't happen, and therefore
the interface could remain marked as down after boot even if carrier is up.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>

drivers/ethernet/nxp_enet/eth_nxp_enet.c

@@ -502,6 +502,8 @@ static void eth_nxp_enet_iface_init(struct net_if *iface)
 	const struct device *dev = net_if_get_device(iface);
 	struct nxp_enet_mac_data *data = dev->data;
 	const struct nxp_enet_mac_config *config = dev->config;
+	const struct device *phy_dev = config->phy_dev;
+	struct phy_link_state state;
 
 	net_if_set_link_addr(iface, data->mac_addr,
 			     sizeof(data->mac_addr),
@@ -518,6 +520,14 @@ static void eth_nxp_enet_iface_init(struct net_if *iface)
 	ethernet_init(iface);
 	net_if_carrier_off(iface);
 
+	/* In case the phy driver doesn't report a state change due to link being up
+	 * before calling phy_configure, we should check the state ourself, and then do a
+	 * pseudo-callback
+	 */
+	phy_get_link_state(phy_dev, &state);
+
+	nxp_enet_phy_cb(phy_dev, &state, (void *)dev);
+
 	config->irq_config_func();
 
 	nxp_enet_driver_cb(config->mdio, NXP_ENET_MDIO, NXP_ENET_INTERRUPT_ENABLED, NULL);