nvme: set initial value for controller's numa node

Initialize the node to NUMA_NO_NODE value. Transports that are aware of
numa node affinity can override it (e.g. RDMA transport set the affinity
according to the RDMA HCA).

Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>