net: mscc: ocelot: remove unnecessary variable

Commit 2f187bfa

 ("net: ethernet: ocelot: remove the need for num_stats
initializer") added a flags field to the ocelot stats structure. The same
behavior can be achieved without this additional field taking up extra
memory.

Remove this structure element to free up RAM

Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>