net: mscc: ocelot: separate the implementation of switch reset

The Felix switch has a different reset procedure, so a function pointer
needs to be created and added to the ocelot_ops structure.

The reset procedure has been moved into ocelot_init.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>