RDMA/bnxt_re: Optimize the bnxt_re_init_hwrm_hdr usage

RDMA/bnxt_re: Optimize the bnxt_re_init_hwrm_hdr usage

As of now bnxt_re_init_hwrm_hdr is taking only the opcode from the
caller. compl_ring and target_id field is always -1. These fields might be
changed when newer features are added. For now, removing these parameters
as they are hard coded. Also, remove the rdev field which is not used.

Also, initialize the structure bnxt_fw_msg during declaration itself.

Link: https://lore.kernel.org/r/1686679943-17117-4-git-send-email-selvin.xavier@broadcom.com
Suggested-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>