net: phy: mscc: improved serdes calibration applied to VSC8514

The current IB serdes calibration algorithm (performed by the onboard 8051)
has proven to be unstable for the VSC8514 QSGMII phy.
A new algorithm has been developed based on
'Frequency-offset Jittered-Injection' or 'FoJi' method which solves
all known issues.  This patch disables the 8051 algorithm and
replaces it with the new FoJi algorithm.
The calibration is now performed in a new file (mscc_serdes.c),
which can act as an placeholder for future serdes configurations.

Fixes: e4f9ba64

 ("net: phy: mscc: add support for VSC8514 PHY.")
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: Bjarni Jonasson <bjarni.jonasson@microchip.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>