IB/rxe: Add port protocol stats

Expose new counters using the get_hw_stats callback.
We expose the following counters:

+---------------------+----------------------------------------+
|      Name           |           Description                  |
|---------------------+----------------------------------------|
|sent_pkts            | number of sent pkts                    |
|---------------------+----------------------------------------|
|rcvd_pkts            | number of received packets             |
|---------------------+----------------------------------------|
|out_of_sequence      | number of errors due to packet         |
|                     | transport sequence number              |
|---------------------+----------------------------------------|
|duplicate_request    | number of received duplicated packets. |
|                     | A request that previously executed is  |
|                     | named duplicated.                      |
|---------------------+----------------------------------------|
|rcvd_rnr_err         | number of received RNR by completer    |
|---------------------+----------------------------------------|
|send_rnr_err         | number of sent RNR by responder        |
|---------------------+----------------------------------------|
|rcvd_seq_err         | number of out of sequence packets      |
|                     | received                               |
|---------------------+----------------------------------------|
|ack_deffered         | number of deferred handling of ack     |
|                     | packets.                               |
|---------------------+----------------------------------------|
|retry_exceeded_err   | number of times retry exceeded         |
|---------------------+----------------------------------------|
|completer_retry_err  | number of times completer decided to   |
|                     | retry                                  |
|---------------------+----------------------------------------|
|send_err             | number of failed send packet           |
+---------------------+----------------------------------------+

Signed-off-by: Yonatan Cohen <yonatanc@mellanox.com>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Andrew Boyer <andrew.boyer@dell.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>