RDMA/efa: Add EFA device definitions

EFA PCIe device implements a single Admin Queue (AQ) and Admin Completion
Queue (ACQ) pair to initialize and communicate configuration with the
device.  Through this pair, we run set/get commands for querying and
configuring the device, create/modify/destroy queues, and IB specific
commands like Address Handler (AH), Memory Registration (MR) and
Protection Domains (PD).

In addition to admin (AQ/ACQ), we have data path queues that get
classified as Queue Pairs (QP) and Completion Queues (CQ).

Signed-off-by: Gal Pressman <galpress@amazon.com>
Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>