bnx2x: Add Geneve inner-RSS support

This adds the ability to perform RSS hashing based on encapsulated
headers for a geneve-encapsulated packet.

This also changes the Vxlan implementation in bnx2x to be uniform
for both vxlan and geneve [from configuration perspective].

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>