api: sched: clarify usage of PRIO_DEFAULT
api: sched: clarify usage of PRIO_DEFAULT

Default prio is used when priority scheduling is not important.

Signed-off-by: Petri Savolainen <d528fd253b9aaf78fa72edbcc6249e82047f6ce6@nokia.com>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

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