Comparing the ethtool output from phylink and non-phylink fixed-link
setups shows that we have some differences:

- The "auto-negotiation" fields are different; phylink reports these
  as "No", non-phylink reports these as "Yes" for the supported and
  advertising masks.
- The link partner advertisement is set to the link speed with non-
  phylink, but phylink leaves this unset, causing all link partner
  fields to be omitted.

The phylink ethtool output also disagrees with the software emulated
PHY dump via the MII registers.

Update the phylink fixed-link parsing code so that we better reflect
the behaviour of the non-phylink code that this facility replaces, and
bring the ethtool interface more into line with the report from via the
MII interface.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>