mm/sparse: skip no-map memblock check when fill_subsection_map

When mhp use sparse_add_section, don't check no-map region,
so that to allow no-map reserved memory to get struct page
support.

Signed-off-by: Li Chen <lchen@ambarella.com>
Change-Id: I0d2673cec1b66adf695251037a00c240976b226f

mm/sparse.c

@@ -692,7 +692,9 @@ static int fill_subsection_map(unsigned long pfn, unsigned long nr_pages)
 
 	if (bitmap_empty(map, SUBSECTIONS_PER_SECTION))
 		rc = -EINVAL;
-	else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION))
+	else if (memblock_is_map_memory(PFN_PHYS(pfn)) &&
+		 bitmap_intersects(map, subsection_map,
+				   SUBSECTIONS_PER_SECTION))
 		rc = -EEXIST;
 	else
 		bitmap_or(subsection_map, map, subsection_map,