RDS: Add support for fast registration work request

RDS: Add support for fast registration work request

This patch adds support for MR registration through work request in RDS,
commonly referred as FRWR/fastreg/FRMR.

With this patch added, RDS chooses the registration method, between FMR
and FRWR, based on the preference given through 'prefer_frwr' module
parameter and the support offered by the underlying device.

Please note that this patch is adding support for MR registration done
only through CMSG. Support for registrations through RDS_GET_MR socket
option will be added through another patch.

Orabug: 22145384

Suggested-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Avinash Repaka <avinash.repaka@oracle.com>
Tested-by: Gerald Gibson <gerald.gibson@oracle.com>
Tested-by: Efrain Galaviz <efrain.galaviz@oracle.com>
Reviewed-by: Wei Lin Guay <wei.lin.guay@oracle.com>