DS8K driver: specify pool and lss in extra-specs

[OpenStack Infra]

https://review.openstack.org/435857
Dear bug triager. This bug was created since a commit was marked with DOCIMPACT.
Your project "openstack/cinder" is set up so that we directly report the documentation bugs against it. If this needs changing, the docimpact-group option needs to be added for the project. You can ask the OpenStack infra team (#openstack-infra on freenode) for help if you need to.

commit b401355c6ffa8e933b72ec9db63496da6998c1f5
Author: Jia Min <email address hidden>
Date: Sun Feb 19 22:32:49 2017 -0700

    DS8K driver: specify pool and lss in extra-specs

    DS8K driver needs two new properties in extra-specs, so that user
    can specify pool or lss or both of them to allocate volume in their
    expected area.

    On the other hand, driver needs to verify the pool and lss user
    set to avoid they set wrong pool or lss.

    DocImpact
    Implements: blueprint specify-pool-lss
    Change-Id: Ibd98fa3246118aa6ad5d86ecbfe46ae78de87716