Merge branch 'b44'

Hauke Mehrtens says:

====================
b44: add support for external PHY

This adds support for an external phy connected to the mac controlled
by b44. This is used on home routers of the BCM47xx line where this MAC
core was used and is contended to an external switch core through MII.
These patches are in OpenWrt for some time and are tested by different
users with different devices.

The publicly available Programmer's Reference Guide for some of these
chips help making this patch it would be nice to have such a
documentation for more Broadcom Chips like some SoCs.
https://www.broadcom.com/collateral/pg/440X-PG02-R.pdf
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>