octeontx2-af: Support ESP/AH RSS hashing

octeontx2-af: Support ESP/AH RSS hashing

Support SPI and sequence number fields of
ESP/AH header to be hashed for RSS. By default
ESP/AH fields are not considered for RSS and
needs to be set explicitly as below:
ethtool -U eth0 rx-flow-hash esp4 sdfn
or
ethtool -U eth0 rx-flow-hash ah4 sdfn
or
ethtool -U eth0 rx-flow-hash esp6 sdfn
or
ethtool -U eth0 rx-flow-hash ah6 sdfn

To disable hashing of ESP fields:
ethtool -U eth0 rx-flow-hash esp4 sd
or
ethtool -U eth0 rx-flow-hash ah4 sd
or
ethtool -U eth0 rx-flow-hash esp6 sd
or
ethtool -U eth0 rx-flow-hash ah6 sd

Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Link: https://lore.kernel.org/r/1611378552-13288-1-git-send-email-sundeep.lkml@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>