octeontx2-af: update CPT inbound inline IPsec mailbox

commit 0d99b26511ac825530c0805733766d308b4532d7 from
git@git.assembla.com:cavium/WindRiver.linux.git

Updates CPT inbound inline IPsec configure mailbox to take
CPT credit threshold and bpid, which are introduced
in CN10KB.
And a write to NIX_AF_RX_CPT(0..1)_CREDIT:INST_CRED_CNT,
will add the 2's complement write value to the credit
count. Existing code is not writing correct value to make
INST_CRED_CNT to reset value. This patch fixes the same.

Signed-off-by: Srujana Challa <schalla@marvell.com>
Change-Id: I9305eefb0d063942450909cb5d0f7953741897d8
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/91122


Reviewed-by: Nithin Kumar Dabilpuram <ndabilpuram@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>