Adds `instance_info/kernel_append_params` property support to
`redfish` hardware type. If given, this property overrides
`[redfish]/kernel_append_params` ironic option.
The rationale for adding this property is to allow passing
node-specific kernel parameters to instance kernel.
One of the use-cases for this is to pass node static network
configuration to the kernel.
Change-Id: Ib1617f5a7ab34968d8bfe06fe49f3ba68e56f99f
Story: 2006691
Task: 36988
605f744570