net: mdio: mscc-miim: Handle the switch reset

The mscc-miim device can be impacted by the switch reset, at least when
this device is part of the LAN966x PCI device.

Handle this newly added (optional) resets property.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>