add new 'osmo-arfcn' program to compute frequency based on arfcn

The freq -> arfcn side still needs to be implemented.
diff --git a/utils/Makefile.am b/utils/Makefile.am
new file mode 100644
index 0000000..645cfd5
--- /dev/null
+++ b/utils/Makefile.am
@@ -0,0 +1,5 @@
+INCLUDES = $(all_includes) -I$(top_srcdir)/include
+noinst_PROGRAMS = osmo-arfcn
+
+osmo_arfcn_SOURCES = osmo-arfcn.c
+osmo_arfcn_LDADD = $(top_builddir)/src/libosmocore.la $(top_builddir)/src/gsm/libosmogsm.la