staging: dpaa2-switch: enable the control interface

Enable the CTRL_IF of the switch object, now that all the pieces are in
place (buffer and queue management, interrupts, NAPI instances etc).

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>