infiniband: fix mlx4 kconfig dependency warning

Fix kconfig dependency warning to satisfy dependencies:

warning: (MLX4_EN && NETDEVICES && NETDEV_10000 && PCI && INET || MLX4_INFINIBAND && INFINIBAND) selects MLX4_CORE which has unmet direct dependencies (NETDEVICES && NETDEV_10000 && PCI)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>