Merge branch 'mlx4-const-dev_addr'

Jakub Kicinski says:

====================
mlx4: prep for constant dev->dev_addr

This patch converts mlx4 for dev->dev_addr being const. It converts
to use of common helpers but also removes some seemingly unnecessary
idiosyncrasies.

Please review.
====================

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