ionic: Add basic adminq support

Most of the NIC configuration happens through the AdminQ message
queue.  NAPI is used for basic interrupt handling and message
queue management.  These routines are set up to be shared among
different types of queues when used in slow-path handling.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>