Merge branch 'tc-gate-offload-for-SJA1105-DSA-switch'

Vladimir Oltean says:

====================
tc-gate offload for SJA1105 DSA switch

Expose the TTEthernet hardware features of the switch using standard
tc-flower actions: trap, drop, redirect and gate.

v1 was submitted at:
https://patchwork.ozlabs.org/project/netdev/cover/20200503211035.19363-1-olteanv@gmail.com/

v2 was submitted at:
https://patchwork.ozlabs.org/project/netdev/cover/20200503211035.19363-1-olteanv@gmail.com/

Changes in v3:
Made sure there are no compilation warnings when
CONFIG_NET_DSA_SJA1105_TAS or CONFIG_NET_DSA_SJA1105_VL are disabled.

Changes in v2:
Using a newly introduced dsa_port_from_netdev public helper.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>