Update raid config spec to add one more RPC API
Update raid config spec to add one more RPC API

This commit updates the spec for RAID interface
in Ironic to add one more RPC API set_target_raid_config.
This is required for updating the target_raid_config
for the node.

Change-Id: I39b2601f0e99aad1ae72619cb2c7ab7ffcd060d9

NaohiroTamura/ironic-specs,openstack/ironic-specs,bcornec/ironic-specs,naterh/ironic-specs