This patch introduces a new define: VSC73XX_MAX_NUM_PORTS, which can be
used in the future instead of a hardcoded value.
Currently, the only hardcoded value is vsc->ds->num_ports. It is being
replaced with the new define.
Suggested-by: Vladimir Oltean <olteanv@xxxxxxxxx>
Signed-off-by: Pawel Dembicki <paweldembicki@xxxxxxxxx>