gve: Add netif_set_xps_queue call

Configure XPS when adding tx queues to the notification blocks.

Fixes: dbdaa675

 ("gve: Move some static functions to a common file")
Signed-off-by: Catherine Sullivan <csully@google.com>
Signed-off-by: David Awogbemila <awogbemila@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>