Merge branch 'bcm_sf2-utilize-b53_common'

Florian Fainelli says:

====================
net: dsa: Make bcm_sf2 utilize b53_common

This patch series makes the bcm_sf2 driver utilize a large number of the core
functions offered by the b53_common driver since the SWITCH_CORE registers are
mostly register compatible with the switches driven by b53_common.

In order to accomplish that, we just override the dsa_driver_ops callbacks that
we need to. There are still integration specific logic from the bcm_sf2 that we
cannot absorb into b53_common because it is just not there, mostly in the area
of link management and power management, but most of the features are within
b53_common now: VLAN, FDB, bridge

Along the process, we also improve support for the BCM58xx SoCs, since those
also have the same version of the switching IP that 7445 has (for which bcm_sf2
was developed).

Changes in v3:

- rebase against 145dd5f9c88f6ee645662df0be003e8f04bdae93 ("net: flush the
  softnet backlog in process context")

Changes in v2:

- rebased against "net: dsa: rename switch operations structure"
====================

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