iommu/amd: X2apic mode: setup the INTX registers on mask/unmask

This is more logically correct and will also allow us to
to use mask/unmask logic to restore INTX setttings after
the resume from s3/s4.

Fixes: 66929812 ("iommu/amd: Add support for X2APIC IOMMU interrupts")

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20211123161038.48009-4-mlevitsk@redhat.com


Signed-off-by: Joerg Roedel <jroedel@suse.de>