RDMA/bnxt_re: expose detailed stats retrieved from HW

Broadcom's adapter supports more granular statistics
to allow better understanding about the state of the
chip when data traffic is flowing.

Exposing the detailed stats to the consumer through
the standard hook available in the kverbs interface.
In order to retrieve all the information, driver
implements a firmware command.

Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>