octeontx2-af: refactor function npc_install_flow for default entry

octeontx2-af: refactor function npc_install_flow for default entry

This patch refactors npc_install_flow function to install AF
installed default MCAM entries similar to other MCAM entries
installed by PF/VF. As a result the code would be more readable
and easy to maintain. Modified npc_verify_entry and npc_verify_channel
to properly check MCAM rules installed by AF.

Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>