octeontx2-af: cn10k: Add mailbox to configure reassembly timeout

CN10K CPT coprocessor includes a component named RXC which
is responsible for reassembly of inner IP packets. RXC has
the feature to evict oldest entries based on age/threshold.
This patch adds a new mailbox to configure reassembly age
or threshold.

Signed-off-by: Jerin Jacob Kollanukkaran <jerinj@marvell.com>
Signed-off-by: Srujana Challa <schalla@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>