drivers: net: emac: add Atheros AR8035 phy initialization code

This patch adds the phy initialization code for Qualcomm
Atheros AR8035 phy. This configuration is found in the
Cisco Meraki MR24.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>