In the previous refactoring serise there were few leftover functions which
are not is use anymore.  Removed them as it is a dead code.

Fixes: 6f53196b ("RDMA/bnxt_re: Refactor doorbell management functions")
Link: https://lore.kernel.org/r/1585851136-2316-5-git-send-email-devesh.sharma@broadcom.comSigned-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>