Merge branch 'b53-nsp-switch'

Florian Fainelli says:

====================
net: dsa: b53: Add Broadcom NSP switch support

This patch series updates the B53 driver to support Broadcom's Northstar Plus
Soc integrated switch.

Unlike the version of the core present in BCM5301x/Northstar, we cannot read the
full chip id of the switch, so we need to get the information about our switch
id from Device Tree.

Other than that, this is a regular Broadcom Ethernet switch which is register
compatible for all practical purposes with the existing switch driver.

Since DSA requires a working CPU Ethernet MAC driver this depends on Jon
Mason's AMAC/BGMAC driver changes to support NSP. Board specific changes depend
on patches present in Broadcom's ARM SoC branches and will be posted in a short
while.
====================

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>