stats: Set class_id in rate_ctr group descriptions

This commit adds the class_id initialiser to all rate_ctr_group_desc
definitions.

Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
index d7ec545..cc7d442 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_utils.c
@@ -32,6 +32,7 @@
 
 #include <osmocom/core/linuxlist.h>
 #include <osmocom/core/talloc.h>
+#include <osmocom/core/stats.h>
 #include <osmocom/gsm/gsm0808.h>
 #include <osmocom/gsm/ipa.h>
 
@@ -65,6 +66,7 @@
 	.group_description = "NAT BSC Statistics",
 	.num_ctr = ARRAY_SIZE(bsc_cfg_ctr_description),
 	.ctr_desc = bsc_cfg_ctr_description,
+	.class_id = OSMO_STATS_CLASS_PEER,
 };
 
 struct bsc_nat *bsc_nat_alloc(void)