scsi: lpfc: Separate NVMET RQ buffer posting from IO resources SGL/iocbq/context

Currently IO resources are mapped 1 to 1 with RQ buffers posted

Added logic to separate RQE buffers from IO op resources
(sgl/iocbq/context). During initialization, the driver will determine
how many SGLs it will allocate for NVMET (based on what the firmware
reports) and associate a NVMET IOCBq and NVMET context structure with
each one.

Now that hdr/data buffers are immediately reposted back to the RQ, 512
RQEs for each MRQ is sufficient. Also, since NVMET data buffers are now
128 bytes, lpfc_nvmet_mrq_post is not necessary anymore as we will
always post the max (512) buffers per NVMET MRQ.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>