RDMA/bnxt_re: Initialize Doorbell pacing feature

RDMA/bnxt_re: Initialize Doorbell pacing feature

Checks for pacing feature capability and get the doorbell pacing
configuration using FW commands. Allocate a page and initialize
the pacing parameters for the applications. Cleanup the page and
de-initialize the pacing during device removal.

Link: https://lore.kernel.org/r/1689742977-9128-4-git-send-email-selvin.xavier@broadcom.com
Signed-off-by: Chandramohan Akula <chandramohan.akula@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>