mlx5: Add driver for Mellanox Connect-IB adapters

The driver is comprised of two kernel modules: mlx5_ib and mlx5_core.
This partitioning resembles what we have for mlx4, except that mlx5_ib
is the pci device driver and not mlx5_core.

mlx5_core is essentially a library that provides general functionality
that is intended to be used by other Mellanox devices that will be
introduced in the future.  mlx5_ib has a similar role as any hardware
device under drivers/infiniband/hw.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
[ Merge in coccinelle fixes from Fengguang Wu <fengguang.wu@intel.com>.
  - Roland ]

Signed-off-by: Roland Dreier <roland@purestorage.com>