Merge branch 'Continue-towards-using-linkmode-in-phylib'

Andrew Lunn says:

====================
Continue towards using linkmode in phylib

These patches contain some further cleanup and helpers, and the first
real patch towards using linkmode bitmaps in phylink.

The macro magic in the RFC version has been replaced with run time
initialisation.
====================

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