Add samsung specific changes

mm/sparse-vmemmap.c

@@ -332,7 +332,13 @@ int __meminit vmemmap_populate_hugepages(unsigned long start, unsigned long end,
 			return -ENOMEM;
 
 		pmd = pmd_offset(pud, addr);
+
+		/* avoid pmd size alloc if no altmap */
+#ifdef CONFIG_ARCH_QTI_VM
+		if (pmd_none(READ_ONCE(*pmd)) && altmap) {
+#else
 		if (pmd_none(READ_ONCE(*pmd))) {
+#endif
 			void *p;
 
 			p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);