doc: update hns3 features

doc: update hns3 features

Since the hns3 NIC hardware features are not counted
and it is supported in fact. Besides, the flow director
is not supported and need to delete it.

Fixes: fa29fe45a7b4 ("net/hns3: support queue start and stop")
Fixes: 521ab3e93361 ("net/hns3: add simple Rx path")
Fixes: bba636698316 ("net/hns3: support Rx/Tx and related operations")
Fixes: 936eda25e8da ("net/hns3: support dump register")
Fixes: 53b9f2b9a560 ("doc: update feature list in hns3 guide")
Cc: stable@dpdk.org
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>