Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index cf2af04..532c292 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/pagemap.h>
+#include <linux/hugetlb.h>
 #include <asm/tlb.h>
 #include <asm-generic/pgtable.h>