Add the 'dedicated_cpus' section in metadata API service to tell the instance CPUs that are set as 'dedicated' CPUs if instance has any dedicated CPUs. If instance is using a 'shared' CPU allocation policy, it reports 'None' for no dedicated CPU. Part of blueprint use-pcpu-and-vcpu-in-one-instance Change-Id: I3d19195ddefb856c10fa6756dd98850119a4dfcb Signed-off-by: Wang Huaqiang <huaqiang.wang@intel.com>