octeontx2-af: Add L3 and L4 packet verification mailbox

Adds mailbox support for L4 checksum verification
and L3 and L4 length verification configuration.

Signed-off-by: Vidhya Raman <vraman@marvell.com>
Signed-off-by: Jerin Jacob <jerinj@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>