api: pktio: add input and output modes to make pktio one way
api: pktio: add input and output modes to make pktio one way

Add extra mode to disable inputs and/or outputs from a packet io.
This can be used to make pktio read-only, write-only or R/W.
Depending on the chosen mode, platform implementation may be able
to reduce usage of H/W resources.

Signed-off-by: Nicolas Morey-Chaisemartin <7188b998d7bb37a035517aa285fa3f5a95344e80@kalray.eu>
Reviewed-by: Petri Savolainen <d528fd253b9aaf78fa72edbcc6249e82047f6ce6@nokia.com>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

ravineet-singh/odp,dkrot/odp,nmorey/odp,nmorey/odp,erachmi/odp,ravineet-singh/odp,dkrot/odp,dkrot/odp,nmorey/odp,ravineet-singh/odp,mike-holmes-linaro/odp,erachmi/odp,ravineet-singh/odp,mike-holmes-linaro/odp,mike-holmes-linaro/odp,mike-holmes-linaro/odp,erachmi/odp,dkrot/odp,nmorey/odp,erachmi/odp