Remove useless action PHY_READ_EFUSE, PHY_READ_MAC_BYTE, PHY_WRITE_MAC_BYTE,
PHY_WRITE_ERI_WORD. And define the new action PHY_MDIO_CHG.

PHY_MDIO_CHG is used to modify the mdio operation. By the way, the
firmware could support setting mac ocp.
Signed-off-by: NHayes Wang <hayeswang@realtek.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>