x86/resctrl: Merge the ctrl_val arrays

Each struct rdt_hw_resource has its own ctrl_val[] array. When CDP is
enabled, two resources are in use, each with its own ctrl_val[] array
that holds half of the configuration used by hardware. One uses the odd
slots, the other the even. rdt_cdp_peer_get() is the helper to find the
alternate resource, its domain, and corresponding entry in the other
ctrl_val[] array.

Once the CDP resources are merged there will be one struct
rdt_hw_resource and one ctrl_val[] array for each hardware resource.
This will include changes to rdt_cdp_peer_get(), making it hard to
bisect any issue.

Merge the ctrl_val[] arrays for three CODE/DATA/NONE resources first.
Doing this before merging the resources temporarily complicates
allocating and freeing the ctrl_val arrays. Add a helper to allocate
the ctrl_val array, that returns the value on the L2 or L3 resource if
it already exists. This gets removed once the resources are merged, and
there really is only one ctrl_val[] array.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jamie Iles <jamie@nuviainc.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lkml.kernel.org/r/20210728170637.25610-22-james.morse@arm.com