This patch adds support for few more RSS key types for flow key
algorithm to compute rss hash index.

Following flow key types have been added.
- Tunnel types like NVGRE, VXLAN, GENEVE.
- L2 offload type ETH_DMAC, Here we will consider only DMAC 6 bytes.
- And extension header IPV6_EXT (1 byte followed by IPV6 header
- Hashing inner protocol fields for inner DMAC, IPv4/v6, TCP, UDP, SCTP.
Signed-off-by: Kiran Kumar K <kirankumark@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>