net: phy: mscc: adding LCPLL reset to VSC8514

At Power-On Reset, transients may cause the LCPLL to lock onto a
clock that is momentarily unstable. This is normally seen in QSGMII
setups where the higher speed 6G SerDes is being used.
This patch adds an initial LCPLL Reset to the PHY (first instance)
to avoid this issue.

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>
Signed-off-by: David S. Miller <davem@davemloft.net>