net/ice: fix freeing queues on DCF device reset

net/ice: fix freeing queues on DCF device reset

In function ice_dcf_stop_queues(), RX queues and TX queues are actually
not freed, so their pointers shall not be set to NULL when queues are
stopped.

This patch adds function call to free queues on DCF device close,
which also set the RX and TX queues' pointers to NULL on freeing
queues, and avoids referring to the released resource when device is
started again.

Fixes: 1a86f4dbdf42 ("net/ice: support DCF device reset")
Cc: stable@dpdk.org
Signed-off-by: Dapeng Yu <dapengx.yu@intel.com>
Acked-by: Qi Zhang <qi.z.zhang@intel.com>