I haven't been able to get link up on a NX_P3_B1 since 2.6.31.  The
driver complains about a firmware hang instead.  When I asked I was
told rev 0x41 was a preproduction rev.  So disable support in the
driver so no one is surprised the code doesn't work.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>