octeontx2-af: Promisc enable/disable through mbox

In legacy silicon, promiscuous mode is only modified
through CGX mbox messages. In CN10KB silicon, it is modified
from CGX mbox and NIX. This breaks legacy application
behaviour. Fix this by removing call from NIX.

Fixes: d6c9784b ("octeontx2-af: Invoke exact match functions if supported")
Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>