dtc: Bump version to v1.4.4

Preparing for yet another release, due to a build bug in v1.4.3.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/Makefile b/Makefile
index f777f50..c3f72e0 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@
 #
 VERSION = 1
 PATCHLEVEL = 4
-SUBLEVEL = 3
+SUBLEVEL = 4
 EXTRAVERSION =
 LOCAL_VERSION =
 CONFIG_LOCALVERSION =