net: phy: Fix the mdix_ctrl changes

PHY drivers to have an eth_tp_mdix_ctrl to indicate what is the configured
MDI setting, and read eth_tp_mdi to indicate what is the current status,

Add new parameter mdix_ctrl in phy_device structure and fix driver.

Signed-off-by: Raju Lakkaraju <Raju.Lakkaraju@microsemi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>