memory: change dirty setting APIs to take a size

Instead of each target knowing or guessing the guest page size,
just pass the desired size of dirtied memory area.

Signed-off-by: Blue Swirl <[email protected]>
diff --git a/xen-all.c b/xen-all.c
index d1fc597..fd39168 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -447,7 +447,8 @@
             j = ffsl(map) - 1;
             map &= ~(1ul << j);
             memory_region_set_dirty(framebuffer,
-                                    (i * width + j) * TARGET_PAGE_SIZE);
+                                    (i * width + j) * TARGET_PAGE_SIZE,
+                                    TARGET_PAGE_SIZE);
         };
     }
 }