Merge branch 'explicit-inbound-link-state'

Florian Fainelli says:

====================
net: enable inband link state negotiation only when explicitly requested

Changes in v5:

- removed an invalid use of the link_update callback in the SF2 driver
  was appeared after merging "net: phy: fixed_phy: handle link-down case"

- reworded the commit message for patch 2 to make it clear what it fixes and
  why this is required

Initial cover letter from Stas:

Hello.

Currently the link status auto-negotiation is enabled
for any SGMII link with fixed-link DT binding.
The regression was reported:
https://lkml.org/lkml/2015/7/8/865
Apparently not all HW that implements SGMII protocol, generates the
inband status for the auto-negotiation to work.
More details here:
https://lkml.org/lkml/2015/7/10/206

The following patches reverts to the old behavior by default,
which is to not enable the auto-negotiation for fixed-link.
The new DT property is added that allows to explicitly request
the auto-negotiation.
====================

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