Merge branch 'genphy-ability'

Heiner Kallweit says:

====================
net: phy: use generic PHY ability readers if callback get_features isn't set

Meanwhile we have generic functions for reading the abilities of
Clause 22 / 45 PHY's. This allows to use them as fallback in case
callback get_features isn't set. Benefit is the reduction of
boilerplate code in PHY drivers.

v2:
- adjust a comment in patch 1 to match the code
====================

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