libnvdimm, of_pmem: use dev_to_node() instead of of_node_to_nid()

libnvdimm, of_pmem: use dev_to_node() instead of of_node_to_nid()

Remove the direct dependency on of_node_to_nid() by using dev_to_node()
instead. Any DT platform device will have its NUMA node id set when the
device is created.

With this, commit 291717b6fbdb ("libnvdimm, of_pmem: workaround OF_NUMA=n
build error") can be reverted.

Fixes: 717197608952 ("libnvdimm: Add device-tree based driver")
Cc: Dan Williams <[email protected]>
Cc: Oliver O'Halloran <[email protected]>
Cc: [email protected]
Signed-off-by: Rob Herring <[email protected]>
Signed-off-by: Dan Williams <[email protected]>