nfp: abm: force Ethternet port up

Current control firmware does not cater too well to multi-host
applications.  There is no way to check which hosts are up or
otherwise negotiate what the state of the external port (the
Ethernet port) should be.  Make sure the link is up when driver
loads, and don't take it down when Ethernet port netdev is
closed.

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>