Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/sh/include/asm/pgtable-3level.h b/arch/sh/include/asm/pgtable-3level.h
index 7d8587e..779260b 100644
--- a/arch/sh/include/asm/pgtable-3level.h
+++ b/arch/sh/include/asm/pgtable-3level.h
@@ -38,6 +38,9 @@
 	return pud_val(pud);
 }
 
+/* only used by the stubbed out hugetlb gup code, should never be called */
+#define pud_page(pud)		NULL
+
 #define pmd_index(address)	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
 {