RDMA/ocrdma: set vlan present bit for user AH

For the AH that describs a VLAN interface details, vlan present bit
needs to be set during posting a WQE. This patch adds the code to
allow it happening.

Signed-off-by: Mitesh Ahuja <mitesh.ahuja@emulex.com>
Signed-off-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>