Remove the 'status' field from the pSeries NX driver data.

The 'status' field isn't used by the driver at all; it simply checks the
devicetree status node at initialization, and returns success if 'okay'
and failure otherwise.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>