RDMA/bnxt_re: introduce wqe mode to select execution path

RDMA/bnxt_re: introduce wqe mode to select execution path

The bnxt_re driver need to decide on how much SQ and RQ memory should to
be allocated and which wqe posting/polling algorithm to use.

Making changes to set the wqe-mode to a default value during device
registration sequence. The wqe-mode is passed to the lower layer driver as
well. Going forward in the lower layer driver wqe-mode will be used to
decide execution path. Initializing the wqe-mode to static wqe type for
now.

Link: https://lore.kernel.org/r/1594822619-4098-2-git-send-email-devesh.sharma@broadcom.com
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>