net:hns: Add Hip06 "RSS(Receive Side Scaling)" support to HNS Driver

This patch adds the support of "RSS (Receive Side Scaling)" feature
provided by the Hip06 ethernet hardware to the HNS ethernet
driver.

This feature helps in distributing the different flows (mapped as
hash by hardware using Toeplitz Hash) to different Queues asssociated
with the processor cores. The mapping of flow-hash values to the
different queues is stored in indirection table (which is per Packet-
parse-Engine/PPE). This patch also provides the changes to re-program
the (flow-hash<->Qid) mapping using the ethtool.

Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Reviewed-by: Kenneth Lee <liguozhu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>