iommu/s390: Fix incorrect pgsize_bitmap

The .pgsize_bitmap property of struct iommu_ops is not a page mask but
rather has a bit set for each size of pages the IOMMU supports. As the
comment correctly pointed out at this moment the code only support 4K
pages so simply use SZ_4K here.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20221025115657.1666860-6-schnelle@linux.ibm.comSigned-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/s390-iommu.c

@@ -12,13 +12,6 @@
 #include <linux/sizes.h>
 #include <asm/pci_dma.h>
 
-/*
- * Physically contiguous memory regions can be mapped with 4 KiB alignment,
- * we allow all page sizes that are an order of 4KiB (no special large page
- * support so far).
- */
-#define S390_IOMMU_PGSIZES	(~0xFFFUL)
-
 static const struct iommu_ops s390_iommu_ops;
 
 struct s390_domain {
@@ -363,7 +356,7 @@ static const struct iommu_ops s390_iommu_ops = {
 	.probe_device = s390_iommu_probe_device,
 	.release_device = s390_iommu_release_device,
 	.device_group = generic_device_group,
-	.pgsize_bitmap = S390_IOMMU_PGSIZES,
+	.pgsize_bitmap = SZ_4K,
 	.get_resv_regions = s390_iommu_get_resv_regions,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= s390_iommu_attach_device,