Kernel params for node are passed by Nailgun

Added kernel parameters to openstack.yaml

Depends on: https://review.openstack.org/#/c/90287/

Closes-Bug: #1295131
Related to bug #1294286
Change-Id: I1fe8ca2b396e36b65ca81d53828e69cd559d8a17
Merge "Kernel params for node are passed by Nailgun"