RDMA/bnxt_re: Change wr posting logic to accommodate variable wqes

Modifying the post-send and post-recv to initialize the wqes slot by slot
dynamically depending on the number of max sges requested by consumer at
the time of QP creation.

Changed the QP creation logic to determine the size of SQ and RQ in 16B
slots based on the number of wqe and number of SGEs requested by consumer

Link: https://lore.kernel.org/r/1594822619-4098-6-git-send-email-devesh.sharma@broadcom.com


Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>