ethernet: use platform_get_ethdev_address()

Use the new platform_get_ethdev_address() helper for the cases
where dev->dev_addr is passed in directly as the destination.

  @@
  expression dev, net;
  @@
  - eth_platform_get_mac_address(dev, net->dev_addr)
  + platform_get_ethdev_address(dev, net)

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>