Merge branch 'net-dsa-hellcreek-add-taprio-offloading'

Kurt Kanzenbach says:

====================
net: dsa: hellcreek: Add TAPRIO offloading

The switch has support for the 802.1Qbv Time Aware Shaper (TAS). Traffic
schedules may be configured individually on each front port. Each port
has eight egress queues. The traffic is mapped to a traffic class
respectively via the PCP field of a VLAN tagged frame.

Previous attempts:
 * https://lkml.kernel.org/netdev/20201121115703.23221-1-kurt@linutronix.de/
 * https://lkml.kernel.org/netdev/20210116124922.32356-1-kurt@linutronix.de/
====================

Link: https://lore.kernel.org/r/20210123105633.16753-1-kurt@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>