net: ethernet: ti: cpsw: fix tx vlan priority mapping

net: ethernet: ti: cpsw: fix tx vlan priority mapping

The CPDMA_TX_PRIORITY_MAP in real is vlan pcp field priority mapping
register and basically replaces vlan pcp field for tagged packets.
So, set it to be 1:1 mapping. Otherwise, it will cause unexpected
change of egress vlan tagged packets, like prio 2 -> prio 5.

Fixes: e05107e6b747 ("net: ethernet: ti: cpsw: add multi queue support")
Reviewed-by: Grygorii Strashko <[email protected]>
Signed-off-by: Ivan Khoronzhuk <[email protected]>
Signed-off-by: David S. Miller <[email protected]>