Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/um/kernel/uml.lds.S b/arch/um/kernel/uml.lds.S
index 36b07ec..9f21443 100644
--- a/arch/um/kernel/uml.lds.S
+++ b/arch/um/kernel/uml.lds.S
@@ -31,6 +31,8 @@
     SCHED_TEXT
     CPUIDLE_TEXT
     LOCK_TEXT
+    IRQENTRY_TEXT
+    SOFTIRQENTRY_TEXT
     *(.fixup)
     /* .gnu.warning sections are handled specially by elf32.em.  */
     *(.gnu.warning)