add the kernel/ramdisk id to driver_info

Because bp https://blueprints.launchpad.net/ironic/+spec/add-node-instance-info
has been completed,
add the deploy_kernel_id and deploy_ramdisk_id to ironic node's driver_info
in stead of to flavor.

Change-Id: I90ffae49212e68749b8331edc278228419317453
Merge "add the kernel/ramdisk id to driver_info"