Merge branch 'net-mii-clause-37-helpers'

Russell King says:

====================
net: mii clause 37 helpers

This is a re-post of two patches that are common to two series that
I've sent in recent weeks; I'm re-posting them separately in the hope
that they can be merged.  No changes from either of the previous
postings.

These patches:

1. convert the existing (unused) mii_lpa_to_ethtool_lpa_x() function
   to a linkmode variant.

2. add a helper for clause 37 advertisements, supporting both the
   1000baseX and defacto 2500baseX variants. Note that ethtool does
   not support half duplex for either of these, and we make no effort
   to do so.
====================

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