Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c
index 0243086..0590f86 100644
--- a/scripts/kconfig/preprocess.c
+++ b/scripts/kconfig/preprocess.c
@@ -114,7 +114,7 @@
 	if (!strcmp(argv[0], "y"))
 		pperror("%s", argv[1]);
 
-	return NULL;
+	return xstrdup("");
 }
 
 static char *do_filename(int argc, char *argv[])