net: dsa: felix: stop calling ocelot_port_{enable,disable}

ocelot_port_enable touches ANA_PORT_PORT_CFG, which has the following
fields:

- LOCKED_PORTMOVE_CPU, LEARNDROP, LEARNCPU, LEARNAUTO, RECV_ENA, all of
  which are written with their hardware default values, also runtime
  invariants. So it makes no sense to write these during every .ndo_open.

- PORTID_VAL: this field has an out-of-reset value of zero for all ports
  and must be initialized by software. Additionally, the
  ocelot_setup_logical_port_ids() code path sets up different logical
  port IDs for the ports in a hardware LAG, and we absolutely don't want
  .ndo_open to interfere there and reset those values.

So in fact the write from ocelot_port_enable can better be moved to
ocelot_init_port, and the .ndo_open hook deleted.

ocelot_port_disable touches DEV_MAC_ENA_CFG and QSYS_SWITCH_PORT_MODE_PORT_ENA,
in an attempt to undo what ocelot_adjust_link did. But since .ndo_stop
does not get called each time the link falls (i.e. this isn't a
substitute for .phylink_mac_link_down), felix already does better at
this by writing those registers already in felix_phylink_mac_link_down.

So keep ocelot_port_disable (for now, until ocelot is converted to
phylink too), and just delete the felix call to it, which is not
necessary.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>