IB/ipoib: Clean up send-only multicast joins

IB/ipoib: Clean up send-only multicast joins

Orabug: 26324050

Even though we don't expect the group to be created by the SM we
sill need to provide all the parameters to force the SM to validate
they are correct.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
(cherry picked from commit c3acdc06a95ff20d920220ecb931186b0bb22c42)

Reviewed-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>