RDMA/ocrdma: Use non-zero tag in SRQ posting

As part of SRQ receive buffers posting we populate a non-zero tag
which will be returned in SRQ receive completions.

Signed-off-by: Selvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>