net: mvpp2: cls: Don't use the sequence attribute for classification

The classifier allows to combine multiple lookups in one "sequence" that
is counted as a single lookup to an engine, with a single result.

We don't actually use that feature, so remove any places where we set
this field, so that the classifier doesn't try to interpret these
fields.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>