net: remove scary warning about EEPROM provided MAC address

In many parts of the computing world having a unique MAC address
sitting in some on-NIC storage is considered the normal case.
Remove the warning to not scare the user unnecessarily.
This applies to Highbank/Midway and ARM's Juno, for instance.
Besides that this fixes the formatting on Midway, for instance,
which currently looks like:
...
Net:   xgmac0
Warning: xgmac0 using MAC address from net device
, xgmac1
Warning: xgmac1 using MAC address from net device
...

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

net/eth.c

@@ -777,8 +777,6 @@ int eth_write_hwaddr(struct eth_device *dev, const char *base_name,
 	} else if (is_valid_ethaddr(dev->enetaddr)) {
 		eth_setenv_enetaddr_by_index(base_name, eth_number,
 					     dev->enetaddr);
-		printf("\nWarning: %s using MAC address from net device\n",
-		       dev->name);
 	} else if (is_zero_ethaddr(dev->enetaddr)) {
 #ifdef CONFIG_NET_RANDOM_ETHADDR
 		net_random_ethaddr(dev->enetaddr);