Merge branch 'bcmgenet-protect-contended-accesses'

Doug Berger says:

====================
net: bcmgenet: protect contended accesses

Some registers may be modified by parallel execution contexts and
require protections to prevent corruption.

A review of the driver revealed the need for these additional
protections.
====================

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