Convert the Altera Triple Speed Ethernet Controller to phylink.
This controller supports MII, GMII and RGMII with its MAC, and
SGMII + 1000BaseX through a small embedded PCS.

The PCS itself has a register set very similar to what is found in a
typical 802.3 ethernet PHY, but this register set memory-mapped instead
of lying on an mdio bus.
Signed-off-by: NMaxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>