RDMA/ocrdma: Fix structure layout for ocrdma_alloc_pd

The udata's for alloc_pd cannot contain u64s due to alignment
constraints. Switch the two never-used u64's to arrays of u32 to reduce
the required struct alignment to 4 bytes.

These reserved fields are totally unnecessary, never written and never
read.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>