Revert "iommu/vt-d: Remove WO permissions on second-level paging entries"

This reverts commit c848416c which is
eea53c58 upstream.

Another iommu patch was backported incorrectly, causing problems, so
drop this as well for the moment.

Reported-by: Wolfgang Müller <wolf@oriole.systems>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>