x86/resctrl: Merge the CDP resources

Now that resctrl uses the schema's configuration type as the source of
CODE/DATA configuration styles, and there is only one configuration
array between the three views of the resource, remove the CODE and DATA
aliases.

This means the arch code only needs to describe the hardware to
resctrl, which will then create the separate CODE/DATA schema
for its ABI.

Add a helper to add schema with a the CDP suffix if CDP is enabled.

Signed-off-by: James Morse <james.morse@arm.com>