net: Revert mlx4 cpumask changes.

This reverts commit 70a640d0
("net/mlx4_en: Use affinity hint") and commit
c8865b64 ("cpumask: Utility function
to set n'th cpu - local cpu first") because these changes break
the build when SMP is disabled amongst other things.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>