Use release helper from libosmocore

Change-Id: I06b9ceff1e1ecfccc1b1a52ffe6b9d3f6dcaa34d
Related: OS#1861
diff --git a/configure.ac b/configure.ac
index 958b48b..6532940 100644
--- a/configure.ac
+++ b/configure.ac
@@ -15,6 +15,10 @@
 dnl kernel style compile messages
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
 
+dnl include release helper
+RELMAKE='-include osmo-release.mk'
+AC_SUBST([RELMAKE])
+
 dnl checks for programs
 AC_PROG_MAKE_SET
 AC_PROG_MKDIR_P