arm_mpam: Detect whether the system can alias PARTIDs

In order to be able to assign multiple PARTIDs freely to resource
control groups, it is necessary that all MSCs that are used by resctrl
either implement PARTID Narrowing (so that PARTIDs can be remapped
explicitly) or otherwise only have controls whose resource regulation
is stateless and so whose behaviour would not be affected by splitting
a control group across multiple PARTIDs.

Detect this property at the RIS level and merge it up the MPAM devices
tree.

Export the common global result as mpam_partid_aliasing, and apply
it to the PARTIDs-per-CLOSID configuration.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>

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Currently, this the logic is simple and may forbid PARTID aliasing
on some systems that can support it as a result of the precise set
of MSCs and controls that are exposed through resctrl.

The aim is to make this logic more flexible later.