memory: Add interface to set iommu page size mask

memory: Add interface to set iommu page size mask

Allow to set the page size mask supported by an iommu memory region.
This enables a vIOMMU to communicate the page size granule supported by
an assigned device, on hosts that use page sizes greater than 4kB.

Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Bharat Bhushan <bbhushan2@marvell.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Message-Id: <20201030180510.747225-8-jean-philippe@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>