hw/virtio/virtio-iommu: Use target-agnostic qemu_target_page_mask()

hw/virtio/virtio-iommu: Use target-agnostic qemu_target_page_mask()

In order to have virtio-iommu.c become target-agnostic,
we need to avoid using TARGET_PAGE_MASK. Get it with the
qemu_target_page_mask() helper.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-Id: <20230524093744.88442-9-philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>