implement support for 3-digit MNC with leading zeros

Receive the mnc_3_digits flag from the PCU interface.

Bump the PCU interface to 9.
This is one part of the three identical pcuif_proto.h patches:
- I49cd762c3c9d7ee6a82451bdf3ffa2a060767947 (osmo-bts)
- I787fed84a7b613158a5618dd5cffafe4e4927234 (osmo-pcu)
- I78f30aef7aa224b2e9db54c3a844d8f520b3aee0 (osmo-bsc)

Add 3-digit flags and use the new RAI and LAI API from libosmocore throughout
the code base to be able to handle an MNC < 100 that has three digits (leading
zeros).

Depends: Id2240f7f518494c9df6c8bda52c0d5092f90f221 (libosmocore),
         Ib7176b1d65a03b76f41f94bc9d3293a8a07d24c6 (libosmocore)

Change-Id: I787fed84a7b613158a5618dd5cffafe4e4927234
diff --git a/include/osmocom/pcu/pcuif_proto.h b/include/osmocom/pcu/pcuif_proto.h
index 00b7bd5..b06077c 100644
--- a/include/osmocom/pcu/pcuif_proto.h
+++ b/include/osmocom/pcu/pcuif_proto.h
@@ -5,7 +5,7 @@
 
 #define PCU_SOCK_DEFAULT	"/tmp/pcu_bts"
 
-#define PCU_IF_VERSION		0x08
+#define PCU_IF_VERSION		0x09
 #define TXT_MAX_LEN	128
 
 /* msg_type */
@@ -122,7 +122,9 @@
 	struct gsm_pcu_if_info_trx trx[8];	/* TRX infos per BTS */
 	uint8_t		bsic;
 	/* RAI */
-	uint16_t	mcc, mnc, lac, rac;
+	uint16_t	mcc, mnc;
+	uint8_t		mnc_3_digits;
+	uint16_t	lac, rac;
 	/* NSE */
 	uint16_t	nsei;
 	uint8_t		nse_timer[7];