add rudimentary NRI support for MSC pooling

This patch served for a manual testing counterpart for osmo-bsc to implement
MSC pooling.

This enables a basic MSC pooling setup, but for a production setup, osmo-msc
would still lack various features related to unloading subscribers to another
MSC as explained in 3GPP TS 23.236.

Change-Id: Iafe0878a0a2c8669080d757b34a398ea75fced36
diff --git a/include/osmocom/msc/vlr.h b/include/osmocom/msc/vlr.h
index 83f83c7..3b9bbc4 100644
--- a/include/osmocom/msc/vlr.h
+++ b/include/osmocom/msc/vlr.h
@@ -269,6 +269,8 @@
 		bool auth_reuse_old_sets_on_error;
 		bool parq_retrieve_imsi;
 		bool is_ps;
+		uint8_t nri_bitlen;
+		struct osmo_nri_ranges *nri_ranges;
 	} cfg;
 	/* A free-form pointer for use by the caller */
 	void *user_ctx;