RDS: Enable use of user named pkey devices

RDS: Enable use of user named pkey devices

RDS code currently derives pkey associated with
a device by parsing its name. With user-named
pkey devices which do not have pkey as part of
the name, that is not possible and ipoib module
exports api to query the pkey from netdev.
Here we switch to use that api instead.

Orabug: 19064704

Ported from parts of UEK2 commit
  a101f6037e882b1c12143416d48345fe7ea62979

Signed-off-by: Mukesh Kacker <mukesh.kacker@oracle.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Reviewed-by: Chien-Hua Yen <chien.yen@oracle.com>
Signed-off-by: Guangyu Sun <guangyu.sun@oracle.com>