soc/intel/xeon_sp/acpi/gen1: Properly set _PXM
Set _PXM in ACPI to indicate which socket the PCI domain belongs to.
TEST: Booted on 2S ocp/tiogapass and checked dmesg that PCI domains are
advertised in the correct Proximity Domain.
Change-Id: I39cec0307b0dce0a4da5df5be5095b8d90758997
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/85172
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Shuo Liu <shuo.liu@intel.com>