Several ACPI static tables contain references to proximity domains.

ACPI 6.3 has clarified that only entries in SRAT may define a new
domain (sec 5.2.16).

Those tables described in the ACPI spec have additional clarifying text.

NFIT: Table 5-132,

"Integer that represents the proximity domain to which the memory
 belongs. This number must match with corresponding entry in the
 SRAT table."

HMAT: Table 5-145,

"... This number must match with the corresponding entry in the SRAT
 table's processor affinity structure ... if the initiator is a processor,
 or the Generic Initiator Affinity Structure if the initiator is a generic
 initiator".

IORT and DMAR are defined by external specifications.

Intel Virtualization Technology for Directed I/O Rev 3.1 does not make any
explicit statements, but the general SRAT statement above will still apply.
https://software.intel.com/sites/default/files/managed/c5/15/vt-directed-io-spec.pdf

IO Remapping Table, Platform Design Document rev D, also makes not explicit
statement, but refers to ACPI SRAT table for more information and again the
generic SRAT statement above applies.
https://developer.arm.com/documentation/den0049/d/

In conclusion, any proximity domain specified in these tables, should be a
reference to a proximity domain also found in SRAT, and they should not be
able to instantiate a new domain.  Hence we switch to pxm_to_node() which
will only return existing nodes.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>