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

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

[ Upstream commit 4691f79d62a637958f7b5f55c232a65399500b7a ]

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: 66929812955bb ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>