x86/resctrl: Add a new node-scoped resource to rdt_resources_all[]

Add a placeholder in the array of struct rdt_hw_resource to be used
for event monitoring of systems with Sub-NUMA Cluster enabled.

Update get_domain_id() to handle SCOPE_NODE.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Peter Newman <peternewman@google.com>