nfp: move refresh tracking into the port structure

Track whether physical port's state have changed since last refresh
inside the nfp_port structure instead of the vNIC structure.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>