Add script to regen library/DIAMETER_Types.ttcn

This way we have a reproducible way to generate the same
library/DIAMETER_Types.ttcn file.

Change-Id: Ie6fdb8003a0faf25a5bf4027b672da73f788988e
diff --git a/Makefile b/Makefile
index 1d5e670..fbd380c 100644
--- a/Makefile
+++ b/Makefile
@@ -110,9 +110,12 @@
 	$(eval $(call DIR_all_template,$(dir)))		\
 	)
 
-.PHONY: tags
+.PHONY: tags regen-diameter-types-ttcn
 tags:
 	find $(shell pwd) \
 		-type f -name "*.ttcn" -o \
 		-type f -name "*.ttcnpp" | \
 	xargs ctags
+
+regen-diameter-types-ttcn:
+	(cd library/ && ./regen-DIAMETER_Types_ttcn.sh)