nfp: interpret extended FW load result codes

To enable easier FW distribution NFP can now automatically
select between FW stored on the flash and loaded from the
kernel.

If FW loading policy is set to auto it will compare the
versions of FW from the host and from the flash and load
the newer one.  If FW type doesn't match (e.g. one advanced
application vs another) the FW from the host takes precedence,
unless one of them is the basic NIC firmware, in which case
the non-basic-NIC FW is selected.

This automatic selection mechanism requires we inform user
what the verdict was.  Print a message to the logs explaining
the decision and the reason.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>