From: Vladimir Oltean <vladimir.oltean@xxxxxxx>
A new tagging protocol implementation based on tag_8021q is on the
horizon, and it appears that it also has to open-code the complicated
logic of finding a source port based on a VLAN header.
Create a single dsa_tag_8021q_find_user() and make sja1105 call it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Signed-off-by: Pawel Dembicki <paweldembicki@xxxxxxxxx>