net/ice: remove bulk alloc option

net/ice: remove bulk alloc option

Remove CONFIG_RTE_LIBRTE_ICE_RX_ALLOW_BULK_ALLOC with below
consideration:

1. A default Rx path can always be selected by setting a proper
   rx_free_thresh value at runtime, see
   ice_check_rx_burst_bulk_alloc_preconditions.

2. Its not a big deal to always reserve more space for desc ring.
   "ring_size = (uint16_t)(rxq->nb_rx_desc + ICE_RX_MAX_BURST);"

3. Fixes a potential invalid memory access in ice_reset_rx_queue.
   If CONFIG_RTE_LIBRTE_ICE_RX_ALLOW_BULK_ALLOC is turned on while
   ice_check_rx_burst_bulk_alloc_preconditions return fail.
   Below code will have problem.

   for (i = 0; i < ICE_RX_MAX_BURST; ++i)
   	rxq->sw_ring[rxq->nb_rx_desc + i].mbuf = &rxq->fake_mbuf;

Fixes: 50370662b727 ("net/ice: support device and queue ops")
Cc: stable@dpdk.org
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>