Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/dax/pmem/Makefile b/drivers/dax/pmem/Makefile
new file mode 100644
index 0000000..010269f
--- /dev/null
+++ b/drivers/dax/pmem/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem.o
+obj-$(CONFIG_DEV_DAX_PMEM) += dax_pmem_core.o
+obj-$(CONFIG_DEV_DAX_PMEM_COMPAT) += dax_pmem_compat.o
+
+dax_pmem-y := pmem.o
+dax_pmem_core-y := core.o
+dax_pmem_compat-y := compat.o