net/octeontx/base: add base PKO operations

net/octeontx/base: add base PKO operations

PKO is the packet output processing unit, which receives the packet
from the core and sends to the BGX interface. This patch adds the
basic PKO operation like open, close, start and stop. These operations
are implemented through mailbox messages and kernel PF driver being the
server to process the message with the logical port identifier.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Signed-off-by: Santosh Shukla <santosh.shukla@caviumnetworks.com>