Merge branch 'sh_eth-optimize-mdio'

Sergei Shtylyov says:

====================
sh_eth: optimize MDIO code

Here's a set of 3 patches against DaveM's 'net-next.git' repo which
gets rid of ~35 LoCs in the MDIO bitbang methods.
====================

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