vfio/iommu_type1: make use of info.flags

The flags entry is there to tell the user that some
optional information is available.

Since we report the iova_pgsizes signal it to the user
by setting the flags to VFIO_IOMMU_INFO_PGSIZES.
Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/vfio_iommu_type1.c

@@ -995,7 +995,7 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
 		if (info.argsz < minsz)
 			return -EINVAL;
 
-		info.flags = 0;
+		info.flags = VFIO_IOMMU_INFO_PGSIZES;
 
 		info.iova_pgsizes = vfio_pgsize_bitmap(iommu);