Add Valgrind leak suppression file

Not sure how to make this file obvious to those that need it, but at least it's here
Ref animetosho/par2cmdline-turbo#36 (comment)

Author: animetosho

gf16/suppressions-valgrind.supp

@@ -0,0 +1,6 @@
+{
+	<gfmat_tables>
+	Memcheck:Leak
+	fun:malloc
+	fun:gfmat_init
+}