nfp: add NSP routine to get static information

Retrieve identifying information from the NSP.  For now it only
contains versions of firmware subcomponents.

Signed-off-by: David Brunecz <david.brunecz@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>